VMS Help  —  Sys Parameters
    Help is provided for the system parameters listed below.

1  –  ACP_BASEPRIO

    ACP_BASEPRIO sets the base priority for all ACPs. The DCL command
    SET PROCESS/PRIORITY can be used to reset the base priorities of
    individual ACPs. ACP_BASEPRIO is not applicable for XQPs.

    ACP_BASEPRIO is a DYNAMIC parameter.

2  –  ACP_DATACHECK

    ACP_DATACHECK controls the consistency checks that are performed
    on internal file system metadata such as file headers.

    ACP_DATACHECK is a bit mask. The following table shows the bits
    that are defined currently:

    Bit        Description

    0          Set this bit to perform consistency checks on read
               operations.

               When this bit is set, the IO$M_DATACHECK function
               modifier is automatically set on all subsequent IO$_
               READLBLK operations that read file system metadata (see
               the OpenVMS I/O User's Reference Manual).

    1          Set this bit to perform consistency checks on write
               operations.

               When this bit is set, the IO$M_DATACHECK function
               modifier is automatically set on all subsequent IO$_
               WRITELBLK operations that read file system metadata
               (see the OpenVMS I/O User's Reference Manual).

    2          Set this bit to perform read-after-write consistency
               checks.

               This is similar to setting bit 1, except that in this
               case the file system does the checks, not the lower
               level device or disk driver.

               Note that read-after-write consistency checks are not
               allowed on deferred writes. Deferred writes are turned
               off if this bit is set.

    3          reserved for VSI use only; must be zero.

    4          reserved for VSI use only; must be zero.

    5 and 6    These two bits control the checks that are performed on
               reads and writes of directory blocks. You can select
               one of four different levels:
                                                 By
                                      Select     Setting
                                      This       Bit 6     And Bit 5
               To Check That...       Level...   to...     to...

               The block is a valid   0          0         0
               directory block
               (reads only)

               The block is a valid   1          0         1
               directory block
               (reads and writes)

               The block is a valid   2          1         0
               directory block
               and contains valid
               entries (reads and
               writes)

               The block is a valid   3          1         1
               directory block
               and contains valid
               entries in correct
               alphanumeric order
               (reads and writes)

               When you set the SYSTEM_CHECK system parameter to 1,
               you enable level 3 checking of directory blocks.

               Write errors result in BUGCHECK and crash your system;
               read errors exit with error status SS$_BADDIRECTORY.

    7          reserved for VSI use only; must be zero.

3  –  ACP_DINDXCACHE

    ACP_DINDXCACHE controls the size of the directory index cache
    and the number of buffers used on a cachewide basis. Also,
    ACP_DINDXCACHE builds a temporary index into the directory
    file, thereby reducing search time and directory header lookup
    operations.

    ACP_DINDXCACHE is an AUTOGEN, DYNAMIC, and FEEDBACK parameter.

4  –  ACP_DIRCACHE

    ACP_DIRCACHE sets the number of pages for caching directory
    blocks. Too small a value causes excessive XQP I/O operations,
    while too large a value causes excessive physical memory to be
    consumed by the directory data block cache.

    ACP_DIRCACHE is an AUTOGEN, DYNAMIC, and FEEDBACK parameter.

5  –  ACP_EXTCACHE

    ACP_EXTCACHE sets the number of entries in the extent cache.
    Each entry points to one contiguous area of free space on disk.
    A specification of 0 means no cache. Too small a value causes
    excessive XQP I/O operations, while too large a value causes
    excessive physical memory to be consumed by the extent cache.

    ACP_EXTCACHE is a DYNAMIC and FEEDBACK parameter.

6  –  ACP_EXTLIMIT

    ACP_EXTLIMIT specifies the maximum amount of free space to
    which the extent cache can point, expressed in thousandths of
    the currently available free blocks on the disk. For example,
    if available free space on the disk is 20,000 blocks, a
    specification of 10 limits the extent cache to 200 blocks.

    The computed, installed value is usually adequate. Users with
    four or more OpenVMS Cluster node systems might want to adjust
    this parameter.

    ACP_EXTLIMIT is a DYNAMIC parameter.

7  –  ACP_FIDCACHE

    ACP_FIDCACHE sets the number of file identification slots cached.
    A specification of 1 means no cache. Too small a value causes
    excessive XQP I/O operations, while too large a value causes
    excessive physical memory to be consumed by the FID caches.

    ACP_FIDCACHE is a DYNAMIC and FEEDBACK parameter.

8  –  ACP_HDRCACHE

    ACP_HDRCACHE sets the number of pages for caching file header
    blocks. Too small a value causes excessive XQP I/O operations,
    while too large a value causes excessive physical memory to be
    consumed by the file header caches.

    ACP_HDRCACHE is an AUTOGEN, DYNAMIC, and FEEDBACK parameter.

9  –  ACP_MAPCACHE

    ACP_MAPCACHE sets the number of pages for caching index file
    bitmap blocks. Too small a value causes excessive XQP I/O
    operations, while too large a value causes excessive physical
    memory to be consumed by the bitmap cache.

    ACP_MAPCACHE is an AUTOGEN, DYNAMIC, and FEEDBACK parameter.

10  –  ACP_MAXREAD

    ACP_MAXREAD sets the maximum number of directory blocks read in
    one I/O operation.

    ACP_MAXREAD is a DYNAMIC parameter.

11  –  ACP_MULTIPLE

    ACP_MULTIPLE enables (1)  or disables (0) the default creation of
    a separate disk XQP cache for each volume mounted on a different
    device type. Prior to Version 4.0, a separate ACP process was
    created for each device type if this parameter was enabled.
    Because ACP operations are now handled by the per process XQP,
    such separate processes are no longer created. In general, having
    multiple caches is unnecessary. One large cache is more efficient
    than several small ones. ACP_MULTIPLE can be overridden on an
    individual-volume basis with the DCL command MOUNT.

    ACP_MULTIPLE is an AUTOGEN and DYNAMIC parameter.

12  –  ACP_QUOCACHE

    ACP_QUOCACHE sets the number of quota file entries cached. A
    specification of 0 means no cache. Too small a value causes
    excessive XQP I/O operations, while too large a value causes
    excessive physical memory to be consumed by the quota caches.

    ACP_QUOCACHE is an AUTOGEN, DYNAMIC, and FEEDBACK parameter.

13  –  ACP_REBLDSYSD

    ACP_REBLDSYSD specifies whether the system disk should be rebuilt
    if it was improperly dismounted with extent caching, file number
    caching, or disk quota caching enabled. The ACP_REBLDSYSD default
    value (1)  ensures that the system disk is rebuilt. Setting the
    value to 0 means the disk is not rebuilt.

    Depending on the amount of caching enabled on the volume
    before it was dismounted, the rebuild operation may consume a
    considerable amount of time. Setting the value of ACP_REBLDSYSD
    to 0 specifies that the disk should be returned to active service
    immediately. If you set ACP_REBLDSYSD to 0, you can enter the DCL
    command SET VOLUME/REBUILD at any time to rebuild the disk.

14  –  ACP_SHARE

    ACP_SHARE enables (0)  or disables (1) the creation of a global
    section for the first ACP used, enabling succeeding ACPs to share
    its code. This parameter should be set to 0 when ACP_MULTIPLE is
    on.

    ACP_SHARE is a DYNAMIC parameter.

15  –  ACP_SWAPFLGS

    ACP_SWAPFLGS enables or disables swap through the value of a
    4-bit number for the following four classes of ACPs:

    Bit    Class of ACP

    0      Disks mounted by MOUNT/SYSTEM

    1      Disks mounted by MOUNT/GROUP

    2      Private disks

    3      Magnetic tape ACP

    If the value of the bit is 1, the corresponding class of ACPs
    can be swapped. The value of decimal 15 (hexadecimal F-all bits
    on) enables swap for all classes of ACP. A value of decimal
    14 disables swap for ACPs for volumes mounted with the /SYSTEM
    qualifier but leaves swap enabled for all other ACPs. Note that
    one has only disk ACPs present if they are specifically requested
    at mount time or if a Files-11 On-Disk Structure Level 1 disk is
    mounted. In general, only bit 3 is significant because usually no
    file ACPs exist.

    ACP_SWAPFLGS is an AUTOGEN and DYNAMIC parameter.

16  –  ACP_SYSACC

    ACP_SYSACC sets the number of directory file control blocks
    (FCBs) that are cached for disks mounted with the /SYSTEM
    qualifier. Each directory FCB contains a 16-byte array containing
    the first letter of the last entry in each block of the directory
    (or group of blocks if the directory exceeds 16 blocks). Since
    entries in a directory are alphabetical, the cached FCB provides
    quick access to a required directory block. This parameter value
    should be roughly equivalent to the number of directories that
    are in use concurrently on each system volume. It might be
    overridden on a per-volume basis with the /ACCESSED qualifier
    to the DCL command MOUNT. The value should be kept low in systems
    with small physical memory and little file activity, because
    the FCBs require a significant amount of space in the nonpaged
    dynamic pool.

    Too small a value causes excessive XQP I/O operations, while too
    large a value causes excessive physical memory to be consumed by
    the FCB caches.

    ACP_SYSACC is an AUTOGEN and DYNAMIC parameter.

17  –  ACP_WINDOW

    ACP_WINDOW sets the default number of window pointers to be
    allocated in a window for a default file access, for disks
    mounted with the /SYSTEM qualifier.

    ACP_WINDOW is a DYNAMIC parameter.

18  –  ACP_WORKSET

    ACP_WORKSET sets the default size of a working set for an ACP.
    A specification of 0 permits the ACP to calculate the size. This
    value should be nonzero only on small systems where memory is
    tight. Too small a value causes excessive ACP page, while too
    large a value causes excessive physical memory to be consumed
    by the ACP. Note that this parameter has no effect on the per-
    process XQP.

    ACP_WORKSET is a DYNAMIC parameter.

19  –  ACP_WRITEBACK

    ACP_WRITEBACK is a dynamic system parameter that controls whether
    deferred writes to file headers are enabled. The default value is
    1, which enables deferred writes to file headers. To disable the
    feature, set ACP_WRITEBACK to 0.

    This system parameter affects only applications like PATHWORKS
    that can request deferred writes to file headers. Note that
    the deferred write feature is not available on Files-11 ODS-1
    volumes.

    ACP_WRITEBACK is a DYNAMIC parameter.

20  –  ACP_XQP_RES

    ACP_XQP_RES controls whether the XQP is currently in memory.
    The default value (1) specifies that the XQP is permanently in
    memory. Change the default only on restricted memory systems
    with a small number of users and little or no file activity that
    requires XQP intervention. Such activity includes file opens,
    closes, directory lookups, and window turns.

21  –  AFFINITY_SKIP

    AFFINITY_SKIP controls the breaking of implicit affinity. The
    value indicates the number of times a process is skipped before
    being moved.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

22  –  AFFINITY_TIME

    AFFINITY_TIME controls the breaking of implicit affinity. The
    value indicates how long a process remains on the compute queue.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

23  –  ALLOCLASS

    ALLOCLASS determines the device allocation class for the system.
    The device allocation class is used to derive a common lock
    resource name for multiple access paths to the same device.

24  –  ARB_SUPPORT

    (Alpha and Integrity servers) The Access Rights Block (ARB)
    compatibility option, the ARB_SUPPORT system parameter, is
    provided specifically to support products that have not yet been
    updated to use the new per-thread security Persona Security Block
    (PSB) data structure instead of the ARB. Changing the value of
    ARB_SUPPORT from 2 or 3 (the default) to any other value can
    affect the operation of these products.

                                   NOTE

       VSI recommends that all Version 7.3-1 systems have the
       ARB_SUPPORT parameter set to 3 (the default). Do not change
       the ARB_SUPPORT parameter to any other value until all
       products dependent on the ARB and associated structures
       have been modified for the new environment.

    The following table describes ARB_SUPPORT parameters:

    ARB_SUPPORT
    Parameter         Value    Behavior

    ISS$C_ARB_NONE    0        The obsolete kernel data cells are not
                               maintained by the system. Fields are
                               initialized to zero (or set to invalid
                               pointers) at process creation.

    ISS$C_ARB_CLEAR   1        The obsolete kernel data cells are
                               cleared (or set to invalid pointers)
                               when the code would have set up values
                               for backward compatibility.

    ISS$C_ARB_READ_   2        The obsolete cells are updated with
    ONLY                       corresponding security information
                               stored in the current PSB when a
                               $PERSONA_ASSUME is issued.

    ISS$C_ARB_FULL    3 (de-   Data is moved from the obsolete cells
                      fault)   to the currently active PSB on any
                               security-based operation.

    ARB_SUPPORT is a DYNAMIC parameter.

25  –  AUTO_DLIGHT_SAV

    AUTO_DLIGHT_SAV is set to either 1 or 0. The default is 0.

    If AUTO_DLIGHT_SAV is set to 1, OpenVMS automatically makes the
    change to and from daylight saving time.

26  –  AWSMIN

    On Alpha and Integrity servers, AWSMIN establishes the lowest
    number of pagelets to which a working set limit can be decreased
    by automatic adjustment of the working set.

    AWSMIN is a DYNAMIC parameter.

27  –  AWSTIME

    AWSTIME specifies the minimum amount of processor time that
    must elapse for the system to collect a significant sample of
    a working set's page fault rate. The time is expressed in units
    of 10 milliseconds. The default value of 5, for example, is 50
    milliseconds.

    Some application configurations that have a large number of
    memory-intensive processes may benefit if the value is reduced.
    The value can be as low as 4.

    AWSTIME expiration is checked only at quantum end. Reducing its
    value and not reducing QUANTUM effectively sets the value of
    AWSTIME equal to the value of QUANTUM.

    AWSTIME is a DYNAMIC parameter.

28  –  BALSETCNT

    BALSETCNT sets the number of balance set slots in the system page
    table. Each memory-resident working set requires one balance set
    slot.

    You can monitor the active system with the DCL command SHOW
    MEMORY or the MONITOR PROCESSES command of the Monitor utility to
    determine the actual maximum number of working sets in memory. If
    this number is significantly lower than the value of BALSETCNT,
    this parameter value could be lowered. If all balance set slots
    are being used, raise the value of BALSETCNT.

    Never set BALSETCNT to a value higher than 2 less than
    MAXPROCESSCNT. If physical memory is a significant system
    constraint, consider lowering this value even further. However,
    if your system runs with a number of processes nearly equal to
    MAXPROCESSCNT, lowering BALSETCNT forces swapping to occur, which
    can affect system performance.

    BALSETCNT is no longer a strict setting of the number of
    processes that might be resident in memory. The swapper tries
    to reduce the number of resident processes down to BALSETCNT.
    However, if the total number of active processes and processes
    that have disabled swapping exceeds BALSETCNT, the swapper does
    not force processes out of memory just to meet the BALSETCNT
    setting.

    BALSETCNT is an AUTOGEN, GEN, DYNAMIC, and MAJOR parameter.

29  –  BORROWLIM

    BORROWLIM defines the minimum number of pages required on the
    free-page list before the system permits process growth beyond
    the working set quota (WSQUOTA) for the process. This parameter
    should always be greater than FREELIM.

    This parameter allows a process to grow beyond the value set by
    the working set quota (WSQUOTA) to the working set quota extent
    (WSEXTENT) on a system that has a substantial memory on the free-
    page list. This automatic working set adjustment also depends
    upon the values of parameters WSINC, PFRATH, and AWSTIME.

    Working set growth attempts to alleviate heavy page faulting. To
    make use of this growth, you must also set the user's WSEXTENT
    authorization quota to a larger number than the WSQUOTA value.

    BORROWLIM is an AUTOGEN, DYNAMIC and MAJOR parameter.

30  –  BREAKPOINTS

    If XDELTA is loaded, BREAKPOINTS enables additional built-in
    calls for XDELTA during the boot sequence. The breakpoints that
    are enabled may change from release to release of OpenVMS.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

    BREAKPOINTS is a DYNAMIC parameter.

31  –  BUGCHECKFATAL

    BUGCHECKFATAL enables or disables the conversion of nonfatal
    bugchecks into fatal bugchecks. The system must be rebooted on a
    fatal bugcheck. A nonfatal bugcheck places an entry only in the
    error log and deletes the corresponding process.

    This parameter should normally be OFF (0);  you should set it ON
    (1)  only when the executive is being debugged.

    Setting the SYSTEM_CHECK parameter to 1 has the effect of setting
    BUGCHECKFATAL to ON (1).

    BUGCHECKFATAL is a DYNAMIC parameter.

32  –  BUGREBOOT

    BUGREBOOT enables or disables automatic rebooting of the system
    if a fatal bugcheck occurs. This parameter should normally be on
    (1);  set it off (0) only when the executive is being debugged.

    BUGREBOOT is a DYNAMIC parameter.

33  –  CHANNELCNT

    CHANNELCNT specifies the maximum number of I/O channels available
    to processes and to the system. The FILLM quota can be used
    to reduce the maximum number of I/O channels for a process. A
    process with a FILLM quota larger than CHANNELCNT is nevertheless
    limited to the maximum number of I/O channels specified by
    CHANNELCNT.

34  –  CLASS_PROT

    CLASS_PROT performs the nondiscretionary classification
    checks. CLASS_PROT is also checked by XQP to determine if a
    classification block should be added to the header of any created
    files.

    CLASS_PROT is a DYNAMIC parameter.

35  –  CLISYMTBL

    CLISYMTBL sets the size of the command interpreter symbol table,
    which controls the number of DCL symbols that can be created.

    CLISYMTBL is a DYNAMIC parameter.

36  –  CLUSTER_CREDITS

    CLUSTER_CREDITS specifies the number of per-connection buffers a
    node allocates to receiving VMS$VAXcluster communications.

    If the SHOW CLUSTER command displays a high number of credit
    waits for the VMS$VAXcluster connection, you might consider
    increasing the value of CLUSTER_CREDITS on the other node.
    However, in large cluster configurations, setting this value
    unnecessarily high consumes a large quantity of nonpaged pool.
    Each receive buffer is at least SCSMAXMSG bytes in size but might
    be substantially larger depending on the underlying transport.

    It is not required for all nodes in the cluster to have the same
    value for CLUSTER_CREDITS.

    The default value is currently 32. Unless a system has very
    constrained memory available, VSI recommends that these values
    not be increased.

37  –  CONCEAL_DEVICES

    CONCEAL_DEVICES enables or disables the use of concealed devices.
    By default, this parameter is set to enable concealed devices
    (1).

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

38  –  CPU_POWER_MGMT_(D)

    On Integrity servers, a CPU can be placed in "low-power mode"
    when it is idle. This minimizes power consumption, thereby
    reducing energy costs for the system. Beginning in Version 8.2-
    1, OpenVMS Integrity servers supports this feature based on the
    settings of two system parameters: CPU_POWER_MGMT and CPU_POWER_
    THRSH.

    A value of 1 for CPU_POWER_MGMT means on (the default); a value
    of 0 means off. Whenever the CPU_POWER_THRSH parameter value is
    exceeded, the operating system places an Integrity processor in
    low-power mode if it is idle. OpenVMS Integrity servers does this
    only if CPU_POWER_MGMT is on. A CPU returns to normal power when
    it receives an interrupt.

    CPU_POWER_MGMT is a DYNAMIC parameter.

39  –  CPU_POWER_THRSH_(D)

    On Integrity servers, CPU_POWER_THRSH is a parameter expressed
    as a percentage. OpenVMS Integrity servers monitors how active
    each CPU is over a fixed time period. If CPU_POWER_MGMT is on
    and a CPU is idle for a period of time indicated by CPU_POWER_
    THRSH, the CPU is placed in a low-power mode if it is idle. A CPU
    returns to normal power when it receives an interrupt.

    For systems supporting real-time operations that require quick
    response time, VSI recommends that this feature be turned off. Use
    of this feature can result in a small performance degradation.

    For more information, see the Intel IA-64 Architecture Software
    Developer's Manual, Volume 2: IA-64 System Architecture.

    See also the CPU_POWER_MGMT parameter.

    CPU_POWER_THRSH is a DYNAMIC parameter.

40  –  CRD_CONTROL

    This special parameter is use by VSI and is subject to change.
    Do not change this parameter unless VSI recommends that you do so.
    On Alpha and Integrity servers, CRD_CONTROL can be used to expand
    the function defined by CRDENABLE.

    CRD_CONTROL is a bit mask for corrected read data (CRD) soft
    error control flags. These flags control the use of CRDERROR
    routines.

    On Alpha and Integrity servers, the following bits are defined:

    Bit    Description

    0      Enables CRD processing for all systems.

    1      Enables scrubbing (rewriting) of the memory location that
           induced the CRD.

    2      Enables page replacement of the pages that exhibit
           repeated CRD errors.

    3      Forces all memory pages to be included in the PFN
           database. On systems that contain more than 512 megabytes
           of memory, all memory is mapped by the PFN database by
           default. This bit allows the mapping to occur on systems
           with less than 512 megabytes of memory.

    4      Enables extended CRD handling, if available.

    5      Enables loading of driver and process for handling server
           management events. Platform-specific code usually sets
           this bit if the required hardware and firmware support are
           available.

    6      Disables CRD throttling.

    7      Disables System Event Log (SEL) polling.

    16-31  Reserved for platform-specific error-handling control.

    On Alpha and Integrity servers, the default setting is 22, which
    enables scrubbing, page replacement, and extended CRD handling.

41  –  CRDENABLE

    (Alpha and Integrity servers) CRDENABLE enables or disables
    detection and logging of memory-corrected read data (ECC) errors.
    This parameter should normally be set to (1).

    Beginning with OpenVMS Version 7.2, CRD_CONTROL can expand the
    function of CRDENABLE. (See CRD_CONTROL.)

42  –  CTLIMGLIM

    CTLIMGLIM specifies the size of the default image I/O segment;
    that is channel table and initial buffer pool for image-related
    file and RMS I/O.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

43  –  CTLPAGES

    CTLPAGES specifies the size of P1 pool. CTLPAGES is automatically
    changed only when the process logical name table, DCL symbols, or
    some layered products require an increase in the size of the P1
    pool area.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

    CTLPAGES is an AUTOGEN parameter.

44  –  CWCREPRC_ENABLE

    CWCREPRC_ENABLE controls whether an unprivileged user can create
    a process on another OpenVMS Cluster node. The default value of 1
    allows an unprivileged user to create a detached process with the
    same UIC on another node. A value of 0 requires that a user have
    DETACH or CMKRNL privilege to create a process on another node.

45  –  DBGTK_SCRATCH

    (Alpha and Integrity servers) DBGTK_SCRATCH specifies how many
    pages of memory are allocated for the remote debugger. This
    memory is allocated only if remote debugging is enabled with the
    8000 boot flag. Normally, the default value is adequate, but if
    the remote debugger issues an error message, you should increase
    this value. See Writing OpenVMS Alpha Device Drivers in C (Margie
    Sherlock and Lenny S. Szubowicz, Digital Press, 1996). for more
    information. (This manual has been archived.)

46  –  DCL_CTLFLAGS

    DCL_CTLFLAGS is a bit mask that alters default behavior for
    certain DCL-related functions on a systemwide basis. However,
    the default values satisfy the needs of most systems.

    Bits 0 and 2 control the formulation of system-generated process
    names for processes created using the SPAWN command or LIB$SPAWN
    library routine. They are provided for compatibility with
    behavior of prior OpenVMS versions. Note that you can eliminate
    the use of system-generated names by supplying your own process
    names.

    Bit 1 controls the token size used by DCL.

    Bit 3 controls the maximum number input parameters to command
    procedure.

    Bit 4 controls the the maximum length for an user name, for which
    OpenVMS mail forwarding address is set.

    DCL_CTLFLAGS bits are described in the following table.

    Bit   Description

    Bit   If clear (the default), the numeric portion of a system-
    0     generated spawned process name is generated randomly. If
          set, the numeric portion is generated sequentially starting
          with sequence number 1.

          The option of sequential generation is provided for
          compatibility with OpenVMS versions prior to Version
          7.3-1. However, this choice can be very expensive in
          performance terms because of the mechanism for finding
          the next available process name. This mechanism attempts to
          create all process names beginning with sequence number 1
          until it finds one that is unused.

          Random generation is the preferred choice because it
          results in a very high probability of finding a unique
          name on the first try.

    Bit   Controls the token size used by DCL. If clear (the
    1     default), this bit instructs DCL to use the traditional
          token size. A token cannot exceed 255 characters. If this
          bit is set, extended tokens are used. Extended tokens are
          4000 characters.

          Note that if you turn on extended tokens, file
          specifications can exceed 255 characters, which might
          require larger structures for parsing file specifications.

    Bit   If clear (the default), the numeric portion of a system-
    2     generated spawned process name has a maximum value of
          65535. If set, the numeric portion of the name has a
          maximum value of 255.

          The option of a maximum of 255 is provided for
          compatibility with OpenVMS versions prior to Version 8.3,
          when it was the only choice. The larger maximum allows many
          more unique spawned process names for a given process.
          For this reason, it is the preferred choice. However,
          the larger maximum uses two additional characters from
          the process name, which might make it more difficult to
          identify users uniquely by looking at their spawned process
          names. If this is an issue on your system, setting bit 2
          might be a better choice.

    Bit   If clear (the default), command procedure supports the
    3     default eight optional parameters (that is, (P1,P2,...P8)).
          If set, command procedure supports up to sixteen optional
          parameters (that is, (P1,P2,...P16)). This is also
          applicable when using the CALL command to transfer control
          to a subroutine.

    Bit   This bit controls the the maximum length for an user name,
    4     for which OpenVMS mail forwarding address is set. If clear
          (the default), user name string length is set to a maximum
          length of 31 characters. If set, user name string length is
          set to a maximum of 255 characters.

          Note: Once this bit is set, user name length is set to
          maximum of 255 characters. Even if this bit is cleared,
          the behavior remains unchanged, that is, supports user name
          length of 255 characters, but there is no way to reset it
          to 31 characters.

47  –  DEADLOCK_WAIT

    DEADLOCK_WAIT defines the number of seconds that a lock request
    must wait before the system initiates a deadlock search on behalf
    of that lock. Setting DEADLOCK_WAIT to zero disables deadlock
    checking. Setting DEADLOCK_WAIT to a value greater than zero
    and less than the default setting provides faster detection of
    deadlocks but requires more CPU usage.

    The DEADLOCK_WAIT value is expressed in seconds; therefore, the
    smallest value you can set is 1 second. Beginning in VSI OpenVMS
    Version 8.3, a subsecond deadlock wait time, which is set in
    the system service $SET_PROCESS_PROPERTIESW item code $PPROP$C_
    DEADLOCK_WAIT, overrides DEADLOCK_WAIT. For more information, see
    the $SET_PROCESS_PROPERTIESW system service in VSI OpenVMS System
    Services Reference Manual.

    DEADLOCK_WAIT is a DYNAMIC parameter.

48  –  DEFGID

    Default POSIX GID used internally by OpenVMS.

49  –  DEFMBXBUFQUO

    DEFMBXBUFQUO sets the default for the mailbox buffer quota size
    in bytes when this value is not specified in a Create Mailbox
    ($CREMBX) system service call.

    DEFMBXBUFQUO is a DYNAMIC parameter.

50  –  DEFMBXMXMSG

    DEFMBXMXMSG sets the default for the mailbox maximum message size
    in bytes when this value is not specified in a Create Mailbox
    ($CREMBX) system service call.

    DEFMBXMXMSG is a DYNAMIC parameter.

51  –  DEFPRI

    DEFPRI sets the base default priority for processes.

    DEFPRI is a DYNAMIC parameter.

52  –  DEFQUEPRI

    DEFQUEPRI establishes the scheduling priority for jobs entered
    in batch and output (printer, server, and terminal) queues when
    no explicit scheduling priority is specified by the submitter.
    The value of this parameter can range from 0 to 255; the default
    value is 100.

    The value of DEFQUEPRI should be less than or equal to MAXQUEPRI.

                                   NOTE

       DEFQUEPRI refers to relative queue scheduling priority, not
       the execution priority of the job.

    DEFQUEPRI is a DYNAMIC parameter.

53  –  DEFUID

    Default POSIX UID used internally by OpenVMS.

54  –  DELPRC_EXIT

    DELPRC_EXIT can be used to control $DELPRC system service options
    that call exit handlers prior to final cleanup and deletion of a
    process. The following table describes these options:

    Option         Description

    0              Disable the exit handler functionality with
                   $DELPRC.

    4              Execute kernel mode exit handlers.

    5 (default)    Execute exec and more privileged mode exit
                   handlers.

    6              Execute supervisor and more privileged mode exit
                   handlers.

    7              Execute user and more privileged mode exit
                   handlers.

    DELPRC_EXIT is a DYNAMIC parameter.

55  –  DEVICE_NAMING

    (Alpha and Integrity servers) DEVICE_NAMING is a bit mask
    indicating whether port allocation classes are used in forming
    SCSI device names.

    Following is the bit definition:

    Bit   Definition

    0     If 1, enable new naming.

    1     Must be 0. This bit is Reserved for use by VSI.

    2     If 1, cloned device unit numbers wrap after 9999(not 65472).

    3     If 1, cloned device unit numbers wrap after 32767(not 65472).

          Note that even if both bits are zero, device unit numbers will
          wrap after 9999 if "nodename$" is prefixed to the name of the
          device in question (e.g. VMS123$DKA100:); devices whose drivers
          support larger device numbers will wrap after 65472 (or 32767
          if bit 3 is set) only if the nodename is not built into the
          device name.

    For more information about port allocation classes, see the VSI
    OpenVMS Cluster Systems manual.

56  –  DISABLE_UPCALLS

    DISABLE_UPCALLS is primarily a debugging aid. It allows the
    system manager to disable threads upcalls of specific types
    for the entire system. The value is a bit mask, with the bits
    corresponding to the upcall types. The upcall types are defined
    in the definition macro $TMCDEF.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

    DISABLE_UPCALLS is a DYNAMIC parameter.

57  –  DISK_QUORUM

    The DISK_QUORUM parameter is the name of an optional quorum disk
    in ASCII. ASCII spaces indicate that no quorum disk is being
    used.

58  –  DISMOUMSG

    DISMOUMSG controls whether the messages that log volume dismounts
    appear on the operator's terminal and in the operator's log. The
    default value of 0 disables reporting of these messages.

    DISMOUMSG is a DYNAMIC parameter.

59  –  DNVOSI1

    DNVOSI1 is reserved to DECnet-Plus for OpenVMS. This special
    parameter is use by VSI and is subject to change. Do not change
    this parameter unless VSI recommends that you do so.

60  –  DORMANTWAIT

    DORMANTWAIT specifies, in seconds, the amount of time that can
    elapse without a significant event before the system treats
    a low-priority computable process as a DORMANT process for
    scheduling purposes. (A low-priority process is a non real-time
    process whose current priority is equal to or less than the value
    specified by the system parameter DEFPRI [default=4].) After
    SUSP (suspended) processes, DORMANT processes are the most likely
    candidates for memory reclamation by the swapper.

    Increasing the value of DORMANTWAIT can increase the interval
    that a low priority process blocks a high priority process if
    that low priority process is holding a lock or resource that the
    higher priority process is waiting for.

    DORMANTWAIT is a DYNAMIC parameter.

61  –  DR_UNIT_BASE

    (Alpha only) DR_UNIT_BASE specifies the base value from which
    unit numbers for DR devices (DIGITAL StorageWorks RAID Array 200
    Family logical RAID drives) are counted.

    DR_UNIT_BASE provides a way for unique RAID device numbers to
    be generated. DR devices are numbered starting with the value of
    DR_UNIT_BASE and then counting from there. For example, setting
    DR_UNIT_BASE to 10 produces device names such as $1$DRA10,
    $1$DRA11, and so on.

    Setting DR_UNIT_BASE to appropriate, nonoverlapping values on all
    cluster members that share the same (nonzero) allocation class
    ensures that no two RAID devices are given the same name.

    DR_UNIT_BASE is a GEN parameter.

62  –  DUMPBUG

    DUMPBUG enables (1)  or disables (0) the writing of error log
    buffers and memory contents to SYS$SYSTEM:SYSDUMP.DMP when a
    fatal bugcheck occurs. This parameter should be off (0)  only
    when the executive is being debugged.

63  –  DUMPSTYLE

    DUMPSTYLE specifies the method of writing system dumps.

    DUMPSTYLE is a 32-bit mask, with the following bits defined.
    Each bit can be set independently. The value of the system
    parameter is the sum of the values of the bits that have been
    set. Remaining or undefined values are reserved for VSI use only.

    Bit              Mask       Description

    0                00000001   0 =  Full dump (SYSGEN default).
                                     The entire contents of physical
                                     memory are written to the dump
                                     file.
                                1 =  Selective dump. The contents of
                                     memory are written to the dump
                                     file selectively to maximize
                                     the usefulness of the dump file
                                     while conserving disk space.

    1                00000002   0 =  Minimal console output.
                                1 =  Full console output (includes
                                     stack dump, register contents,
                                     and so on).
    2                00000004   0 =  Dump to system disk.

                                1 =  Dump off system disk (DOSD) to
                                     an alternate disk. (see the VSI
                                     OpenVMS System Manager's Manual
                                     for details.)

    3 (Alpha and     00000008   0 =  Do not compress.
    Integrity
    servers)
                                1 =  Compress. (VAX systems do not
                                     support dump compression.)

    4 (Alpha and     00000010   0 =  Dump shared memory.
    Integrity
    servers)
                                1 =  Do not dump shared memory. (VAX
                                     systems do not support shared
                                     memory.)

    5 - 14                           reserved for VSI use only.

    15 (VAX only)    00008000   0 =  Disable use of bits 16 - 27.
                                     (Specific to VAX 7000s.)
                                1 =  Enable use of bits 16 - 27.

    16 - 27 (VAX     0FFF0000        Range of DOSD unit numbers. (VAX
    only)                            systems do not support shared
                                     memory.)

    28 - 31                          reserved for VSI use only.

    If you plan to enable the Volume Shadowing minimerge feature on
    an Alpha or Integrity servers disk, be sure to specify DOSD to an
    alternate disk.

                                   NOTE

       On Alpha and Integrity servers, you can save space on
       the system disk and, in the event of a crash, save time
       recording the system memory, by using the OpenVMS Alpha
       and Integrity servers dump compression feature. Unless
       you override the default AUTOGEN calculations (by setting
       DUMPSTYLE in MODPARAMS.DAT), AUTOGEN uses the following
       algorithm:

       o  On a system with less than 128 MB of memory, the system
          sets the DUMPSTYLE to 1 (a raw selective dump) and sizes
          the dump file appropriately.

       o  On a system with 128 MB of memory or greater, the system
          sets the DUMPSTYLE to 9 (a compressed selective dump),
          and creates the dump file at two-thirds the value of the
          corresponding raw dump.

    Examples:

    The mask of 00000006 directs the system to send a full dump, with
    full console output, off the system disk (to the alternate disk).

    For a VAX 7000, a mask of 00098006 directs the system to send a
    full dump with full console output to the DOSD whose unit number
    is 9.

    On Alpha and Integrity servers, the mask of 00000009 directs the
    system to compress a selective dump with minimal console output.

    DUMPSTYLE has AUTOGEN and DYNAMIC attributes.

64  –  ERLBUFFERPAG_S2

    ERLBUFFERPAG_S2 specifies the amount of S2 space memory to
    allocate for each S2 space error log buffer requested by the
    ERRORLOGBUFF_S2 parameter.

    If you increase ERLBUFFERPAG_S2, you must either run AUTOGEN or
    manually increase the size of both the system dump file and the
    error log dump file.

    ERLBUFFERPAG_S2 is an AUTOGEN parameter on Alpha and Integrity
    servers.

65  –  ERLBUFFERPAGES

    ERLBUFFERPAGES specifies the amount of S0 space memory to
    allocate for each S0 space error log buffer requested by the
    ERRORLOGBUFFERS parameter.

    ERLBUFFERPAGES is an AUTOGEN parameter on Alpha and Integrity
    servers.

66  –  ERRORLOGBUFF_S2

    ERRORLOGBUFF_S2 specifies the number of S2 space error log
    buffers reserved for system error log entries. Each buffer
    is ERLBUFFERPAG_S2 in length. If ERRORLOGBUFF_S2 is too low,
    messages might not be written to the error log file. If it is too
    high, the buffers can consume unnecessary physical pages.

    If you increase ERRORLOGBUFF_S2, you must either run AUTOGEN or
    manually increase the size of both the system dump file and the
    error log dump file.

    ERRORLOGBUFF_S2 is an AUTOGEN parameter on Alpha and Integrity
    servers.

67  –  ERRORLOGBUFFERS

    ERRORLOGBUFFERS specifies the number of S0 space error log
    buffers reserved for system error log entries. Each buffer is
    ERLBUFFERPAGES in length. If ERRORLOGBUFFERS is too low, messages
    might not be written to the error log file. If it is too high,
    the buffers can consume unnecessary physical pages.

    ERRORLOGBUFFERS is an AUTOGEN parameter on Alpha and Integrity
    servers.

68  –  EXECSTACKPAGES

    (Alpha and Integrity servers) EXECSTACKPAGES controls the number
    of pages allocated for each RMS exec stack.

    EXECSTACKPAGES is a DYNAMIC parameter.

69  –  EXPECTED_VOTES

    EXPECTED_VOTES specifies the maximum number of votes that can be
    present in a cluster at any given time. Set it to a value that is
    equal to the sum of the vote parameters of all cluster members,
    plus any votes that are contributed by the quorum disk. This
    value is used to automatically derive the number of votes that
    must be present for the cluster to function (quorum).

    EXPECTED_VOTES is an AUTOGEN attribute parameter.

70  –  EXTRACPU

    EXTRACPU sets the time, in units of 10 ms, allotted to each of a
    process's exit handlers (for each access mode) after the process
    times out (that is, reaches its CPU time limit).

    EXTRACPU is a DYNAMIC attribute parameter.

71  –  FAST_PATH

    (Alpha and Integrity servers) FAST_PATH is a static system
    parameter that enables (1) or disables (0) the Fast Path
    performance features for all Fast Path-capable ports.

    Starting in OpenVMS Version 7.2, FAST_PATH is enabled by default.
    In Versions 7.0 and 7.1, FAST_PATH was disabled by default.

    For additional information, see FAST_PATH_PORTS.

72  –  FAST_PATH_PORTS

    (Alpha and Integrity servers) FAST_PATH_PORTS is a static
    parameter that deactivates Fast Path for specific drivers.

    FAST_PATH_PORTS is a 32-bit mask, with a bit assigned for each
    Fast Path port driver. The following table describes the bit
    values:

    Bit
    Value    Description

    1        Indicates that Fast Path is disabled for ports serviced
             by the corresponding driver.

    0        Indicates that Fast Path is not disabled for ports
             serviced by the corresponding driver.

    Beginning in OpenVMS Version 7.3-1, values of specific bit
    positions are those described in the following table:

    Bit
    Position Description

    0        Controls Fast Path for PKQDRIVER (for parallel SCSI).

    1        Controls Fast Path for FGEDRIVER (for Emulex LP7000,
             LP8000, LP9002, LP9802, LP10000 FibreChannel).

    2        Controls Fast Path for PKADRIVER (for Adaptec AIC-78xx
             Ultra3 SCSI).

    3        Controls Fast Path for PEDRIVER (for LAN).

    4        Controls Fast Path for PKRDRIVER (for SMART Array 5300).

    5        Controls Fast Path for PKMDRIVER, the LSI Logic
             LSI53C1030 SCSI port driver.

    6        Controls Fast Path for PGQDRIVER, the Qlogic ISP23xx
             FibreChannel port driver.

    Currently, the default setting for FAST_PATH_PORTS is 0, which
    means that Fast Path is enabled for all drivers that appear in
    the table.

    In addition, note the following:

    o  CI drivers are not controlled by FAST_PATH_PORTS. Fast Path
       for CI is enabled and disabled exclusively by the FAST_PATH
       system parameter.

    o  FAST_PATH_PORTS is relevant only if the FAST_PATH system
       parameter is enabled (equal to 1). Setting FAST_PATH to zero
       has the same effect as setting all the bits in FAST_PATH_PORTS
       to 1.

    For additional information, see FAST_PATH. For an explanation of
    how to set the bits, see the OpenVMS I/O User's Reference Manual.

73  –  FREEGOAL

    FREEGOAL establishes the number of pages that you want to
    reestablish on the free-page list following a system memory
    shortage. Memory shortages occur when the system drops below the
    minimum number of pages required on the free-page list (FREELIM).
    The value of FREEGOAL must always be greater than or equal to the
    value of FREELIM.

    FREEGOAL has the AUTOGEN, DYNAMIC, and MAJOR attributes.

74  –  FREELIM

    FREELIM sets the minimum number of pages that must be on the
    free-page list.

    The system writes pages from the modified-page list, swaps out
    working sets, or reduces the size of the working sets to maintain
    the minimum count.

    While the larger free-page list generally means less page I/O, it
    also means less space for the balance set, which tends to result
    in more swap I/O. You can monitor the size of the free-page list,
    the amount of page, and the amount of swap with the MONITOR IO
    command of the Monitor utility.

    FREELIM has the AUTOGEN and MAJOR attributes.

75  –  GALAXY

    (Alpha Galaxy platforms only) The GALAXY parameter sets memory
    sharing.

    Specify one of the following:

    Value    Description

    0        The default. Do not participate in a memory sharing.

    1        Participate in a memory sharing.

    When you set GALAXY to 1 in a hard partition, OpenVMS instances
    will share memory between soft partitions within that hard
    partition. (You can run more than two soft partitions in a hard
    partition, and you might might not want to share memory among all
    of them.) Note that GALAXY specifies only if a node uses shared
    memory. You do not need to use the parameter to run multiple
    cooperative instances of OpenVMS; you do this by console setup of
    the configuration tree that you want.

76  –  GBLPAGES

    GBLPAGES sets the number of global page table entries allocated
    at bootstrap time. Each global section requires 1 global page
    table entry per section page, plus 2 entries, with the total
    rounded up to an even number.

    Users with CMKRNL privilege can change this parameter on a
    running system. Increasing the value of this parameter allows
    the global page table to expand, on demand, up to the maximum
    size.

    The default value is sufficient for the images normally installed
    as shared in the system startup command procedures. Once the
    system is running and all global sections are created, you can
    examine the actual requirements with the /GLOBAL qualifier of
    the Install utility (INSTALL) and reduce the value of GBLPAGES
    accordingly. However, do not set the value of this parameter
    too low, because the page table entries use little permanently
    resident memory. If you plan to install many user images as
    shared, or if user programs are likely to create many global
    sections, you must increase the value of this parameter.

    GBLPAGES has the AUTOGEN, DYNAMIC, FEEDBACK, GEN, and MAJOR
    attributes.

77  –  GBLPAGFIL

    GBLPAGFIL defines the maximum number of systemwide pages allowed
    for global page-file sections (scratch global sections that can
    be used without being mapped to a file). These global page-
    file sections can be temporary, permanent, system, or group,
    and are allocated from the page file specified in the system
    process header at bootstrap time. When you allow pages for
    global page-file sections, you must increase the size of the
    page file accordingly. Users with CMKRNL privilege can change
    this parameter value on a running system.

    Global page-file sections are created with the Create and Map
    Section system services ($CREATE_GPFILE, $CRMPSC, and $CRMPSC_
    GPFILE_64) without an explicit disk file. These sections are used
    for the RMS global buffers required for shared files. Users of
    shared files should note that global page-file sections cause
    both the global page table and the default system page file
    (PAGEFILE.SYS) to be used. If the value of GBLPAGFIL is too
    small, $CRMPSC issues an error message when you attempt to create
    global page-file sections.

    You must have scratch global sections if you use RMS global
    buffers. Each file using global buffers requires, in the system
    page file, the file's bucket size multiplied by the number of
    global buffers for that file. If the file's bucket size varies,
    as with RMS indexed files, use the maximum bucket size. For
    shared sequential files, use the multiblock count of the first
    stream to perform the $CONNECT service in place of the file's
    bucket size.

    The default value for this parameter is adequate for most
    systems. However, if your site uses RMS global buffering to a
    significant extent, you may need to raise the value of GBLPAGFIL.
    Use the /GLOBAL qualifier of the Install utility to examine
    the number of pages consumed by RMS global buffers. The global
    sections used by RMS for global buffers have the prefix RMS$
    followed by 8 hexadecimal digits.

    Global buffers are enabled with the DCL command SET
    FILE/GLOBAL_BUFFERS, which is described in the VSI OpenVMS DCL
    Dictionary.

    GBLPAGFIL is an AUTOGEN-altered and a DYNAMIC parameter.

78  –  GBLSECTIONS

    GBLSECTIONS sets the number of global section descriptors
    allocated in the system header at bootstrap time. Each global
    section requires one descriptor. Each descriptor takes 32 bytes
    of permanently resident memory.

    The default value is sufficient for the images normally installed
    as shared in the system startup command procedures. Once the
    system is running and all global sections are created, you can
    examine the actual requirements with the /GLOBAL qualifier of the
    Install utility and reduce the value of GBLSECTIONS accordingly.
    However, the value of this parameter should not be set too low.
    If you plan to install many user images as shared, or if user
    programs are likely to create many global sections, you must
    increase the value of this parameter.

    If the value of GBLSECTIONS is too small, you receive a message
    from the Install utility at system startup time or whenever
    you install images manually. Note that too large a value for
    GBLSECTIONS wastes physical memory.

    GBLSECTIONS has the AUTOGEN, FEEDBACK, GEN, and MAJOR attributes.

79  –  GB_CACHEALLMAX

    (Alpha and Integrity servers) If a file is connected to RMS with
    the RMS global buffer DEFAULT option enabled, the number of of
    blocks cached is either a maximum of the GB_CACHEALLMAX parameter
    or a percentage of the file, whichever results in a larger global
    count.

    Note that although a maximum cache size of %x7FFFFFFF is
    supported for an indexed file, sequential and relative file
    organizations are restricted to a maximum cache size of 32767.

    GB_CACHEALLMAX is a DYNAMIC parameter.

80  –  GB_DEFPERCENT

    (Alpha and Integrity servers) If a file is connected to RMS with
    the RMS global buffer DEFAULT option enabled, either a percentage
    (GB_DEFPERCENT) of the file is cached or up to GB_CACHEALLMAX
    blocks of it are cached, whichever results in a larger global
    buffer count. A percentage greater than 100 percent can be
    specified for GB_DEFPERCENT to provide growing room for a file
    in the global cache.

    Note that although a maximum cache size of %x7FFFFFFF is
    supported for an indexed file, sequential and relative file
    organizations are restricted to a maximum cache size of 32767.

    GB_DEFPERCENT is a DYNAMIC parameter.

81  –  GH_EXEC_CODE

    (Alpha and Integrity servers) GH_EXEC_CODE specifies the size in
    pages of the execlet code granularity hint region.

    GH_EXEC_CODE has the AUTOGEN and FEEDBACK attributes.

82  –  GH_EXEC_DATA

    (Alpha and Integrity servers) GH_EXEC_DATA specifies the size in
    pages of the execlet data granularity hint region.

    GH_EXEC_DATA has the AUTOGEN and FEEDBACK parameters.

83  –  GH_RES_CODE

    (Alpha and Integrity servers) GH_RES_CODE specifies the size in
    pages of the resident image code granularity hint region.

    GH_RES_CODE has the AUTOGEN and FEEDBACK attributes.

84  –  GH_RES_CODE_S2

    Specifies the size in pages of the resident 64-bit S2 space
    resident image code granularity hint region.

85  –  GH_RES_DATA

    (Alpha and Integrity servers) GH_RES_DATA specifies the size in
    pages of the resident image data granularity hint region.

    If bit 2 of the LOAD_SYS_IMAGES parameter is set, the image
    LDR$WRAPUP releases all unused pages in the granularity hint
    region at the the end of system startup. The unused pages of the
    resident image granularity hint region are either reserved for
    future use, or given back to the free memory list.

    GH_RES_DATA has the AUTOGEN and FEEDBACK attributes.

86  –  GH_RSRVPGCNT

    GH_RSRVPGCNT specifies the number of pages in the resident image
    code granularity hint region that the Install utility can use
    after the system has finished booting.

    If bit 2 of the LOAD_SYS_IMAGES parameter is set, the image
    LDR$WRAPUP releases all unused pages in the granularity hint
    region at the the end of system startup. The unused pages of the
    resident image granularity hint region are either reserved for
    future use, or given back to the free memory list.

    GH_RSRVPGCNT specifies the number of pages that LDR$WRAPUP
    attempts to leave in the resident image code granularity hint
    region. If the GH_RSRVPGCNT number of pages is larger than the
    unused pages in the granularity hint region, the region is not
    expanded to accommodate the number of pages requested.

    GH_RSRVPGCNT is a FEEDBACK attribute parameter.

87  –  GLX_INST_TMO

    (Alpha Galaxy platforms only) GLX_INST_TMO is the time (in
    milliseconds) that an instance in a Galaxy sharing set can fail
    to increment its timeout value before the other sharing instances
    presume that the instance failed and remove it from the sharing
    set.

    The default is 20,000 ms (20 seconds).

88  –  GLX_SHM_REG

    For Alpha Galaxy systems, GLX_SHM_REG is the number of shared
    memory region structures configured into the Galaxy Management
    Database (GMDB). If set to 0, the default number of shared memory
    regions are configured.

    If the condition value SS$_INSF_SHM_REG is returned for the
    $CRNMPSC_GDZRO_64 system service with the flag SEC$M_SHM_REG, the
    Galaxy shared memory code has run out of internal SHM_REG data
    structures. You need to increase the system parameter GLX_SHM_REG
    and reboot all Galaxy instances with this larger parameter value.

89  –  GROWLIM

    GROWLIM sets the number of pages that the system must have on the
    free-page list so that a process can add a page to its working
    set when it is above quota. GROWLIM has no effect if the process
    is below its working set quota. GROWLIM acts as a fast shutoff
    to the working set extent mechanism based on the system's free
    memory.

    GROWLIM has AUTOGEN, DYNAMIC, and MAJOR attributes.

90  –  IEEE_ADDRESS

    IEEE_ADDRESS is reserved for VSI use only.

91  –  IEEE_ADDRESSH

    IEEE_ADDRESSH is reserved for VSI use only.

92  –  IJOBLIM

    IJOBLIM sets the maximum number of interactive jobs that can be
    on the system concurrently. You can control the maximum number of
    concurrent interactive users on the system with the DCL command
    SET LOGINS/INTERACTIVE.

    IJOBLIM is a DYNAMIC parameter.

93  –  IMGIOCNT

    IMGIOCNT specifies the default number of pages of image I/O
    address space to be allocated for the image activator if not
    specified at program link time.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

94  –  IMGREG_PAGES

    (Alpha and Integrity servers) IMGREG_PAGES is the number of
    pages to reserve in P1 space for images to be installed with
    shareable address data. If IMGREG_PAGES is set to 0, no images
    are installed with shared address data. The default is 10,000
    pages.

    For more information, see the INSTALL section in the VSI OpenVMS
    System Management Utilities Reference Manual.

95  –  IO_PRCPU_BITMAP

    (Alpha and Integrity servers) This parameter is a bitmap
    representing up to 1024 CPUs. Each bit set in this bitmap
    indicates that the corresponding CPU is available for use as a
    Fast Path preferred CPU.

    IO_PRCPU_BITMAP defaults to all bits set. (CPU 0 through CPU 1023
    are all enabled for Fast Path port assignment.)

    You might want to disable the primary CPU from serving as a
    preferred CPU by leaving its bit clear in IO_PRCPU_BITMAP, which
    reserves the primary CPU for non-Fast Path IO operations to use.

    To change the value of IO_PRCPU_BITMAP in SYSBOOT or SYSGEN,
    specify a list of individual bits or contiguous groups of bits.
    For example:

       SYSGEN> SET IO_PRCPU_BITMAP 0,5,17-21

    This command sets bits 0, 5, 17, 18, 19, 20, and 21 in the bitmap
    and clears all other bits.

    Changing the value of IO_PRCPU_BITMAP causes the FASTPATH_SERVER
    process to run the automatic assignment algorithm that spreads
    Fast Path ports evenly among the new set of usable CPUs.

    For additional information, see FAST_PATH and FAST_PATH_PORTS.

    This parameter replaces IO_PREFER_CPU.

96  –  IOTA

    IOTA specifies the amount of time (in 10-millisecond units) to
    charge to the current residence quantum for each voluntary wait.
    The correct value approximates the cost of a disk I/O neglecting
    wait time.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

97  –  IRPCOUNT

    IRPCOUNT sets the number of preallocated intermediate request
    packets. Each packet requires 160 bytes of permanently resident
    memory. If IRPCOUNT is too large, physical memory is wasted.
    If IRPCOUNT is too small, the system increases its value
    automatically, as needed, to permit proper performance.
    However, the system cannot increase IRPCOUNT beyond the value
    of IRPCOUNTV.

    Allowing this growth causes a physical memory penalty. If
    IRPCOUNT is underconfigured, the penalty is 4 percent of physical
    memory from the configured value to the actual value on the
    running system.

    You can use the DCL command SHOW MEMORY/POOL/FULL to determine
    IRPCOUNT usage.

    IRPCOUNT has the GEN and MAJOR attributes.

98  –  IRPCOUNTV

    IRPCOUNTV establishes the upper limit to which IRPCOUNT can be
    automatically increased by the system.

    If this parameter is set too low, system performance can be
    adversely affected because IRPCOUNTV cannot be used for nonpaged
    pool requests.

    A physical memory penalty of 1 percent results for any unused
    growth space (1 longword for every 3 unused intermediate request
    packets).

    IRPCOUNTV has the GEN attribute.

99  –  JBOBLIM

    This parameter is no longer in use.

100  –  JOBCTLD

    System managers do not usually alter JOBCTLD; this word of debug
    flags is used in rolling upgrades of OpenVMS. If bit 0 is set,
    the queue manager does not start. The default is 0.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

101  –  KSTACKPAGES

    (Alpha and Integrity servers) KSTACKPAGES controls the number of
    pages allocated for process kernel stacks.

102  –  LAN_FLAGS

    (Alpha and Integrity servers) LAN_FLAGS is a bit mask used to
    enable features in the local area networks port drivers and
    support code. The default value for LAN_FLAGS is 0.

    The bit definitions are as follows:

    Bit        Description

    0          The default of zero indicates that ATM devices run in
               SONET mode. If set to 1, this bit indicates ATM devices
               run in SDH mode.

    1          If set, this bit enables a subset of the ATM trace
               and debug messages in the LAN port drivers and support
               code.

    2          If set, this bit enables all ATM trace and debug
               messages in the LAN port drivers and support code.

    3          If set, this bit runs UNI 3.0 over all ATM adapters.
               (Auto-sensing of the ATM UNI version is enabled if both
               bit 3 and bit 4 are off (0).)

    4          If set, this bit runs UNI 3.1 over all ATM adapters.
               (Auto-sensing of the ATM UNI version is enabled if both
               bit 3 and bit 4 are off (0).)

    5          If set, disables auto-negotiation over all Gigabit
               Ethernet Adapters.

    6          If set, enables the use of jumbo frames over all
               Gigabit Ethernet Adapters.

    7          Reserved.

    8          If set, disables the use of flow control over all LAN
               adapters that support flow control.

    9          Reserved.

    10         Reserved.

    11         If set, disables the logging of error log entries by
               LAN drivers.

    12         If set, enables a fast timeout on transmit requests,
               usually between 1 and 1.2 seconds instead of 3 to 4
               seconds, for most LAN drivers.

    13         If set, transmits that are given to the LAN device
               and never completed by the device (transmit timeout
               condition) are completed with error status (SS$_ABORT)
               rather than success status (SS$_NORMAL).

    LAN_FLAGS is a DYNAMIC parameter.

103  –  LCKMGR_CPUID

    (Alpha and Integrity servers) LCKMGR_CPUID controls the CPU that
    the Dedicated CPU Lock Manager runs on. This is the CPU that the
    LCKMGR_SERVER process utilizes if you turn this feature on with
    the LCKMGR_MODE system parameter.

    If the specified CPU ID is either the primary CPU or a
    nonexistent CPU, the LCKMGR_SERVER process utilizes the lowest
    nonprimary CPU. For more information, see the LCKMGR_MODE system
    parameter.

    LCKMGR_CPUID is a DYNAMIC parameter.

104  –  LCKMGR_MODE

    (Alpha and Integrity servers) The LCKMGR_MODE parameter controls
    use of the Dedicated CPU Lock Manager. Setting LCKMGR_MODE to a
    number greater than zero (0) indicates the number of CPUs that
    must be active before the Dedicated CPU Lock Manager is turned
    on.

    The Dedicated CPU Lock Manager performs all locking operations
    on a single dedicated CPU. This can improve system performance
    on large SMP systems with high MP_Synch associated with the lock
    manager.

    If the number of active CPUs is greater than or equal to LCKMGR_
    MODE, a LCKMGR_SERVER process is created to service locking
    operations. This process runs at a real-time priority of 63 and
    is always current.

    In addition, if the number of active CPUs should ever be reduced
    below the required threshold by either a STOP/CPU command or by
    a CPU reassignment in a Galaxy configuration, the Dedicated CPU
    Lock Manager automatically turns off within one second, and the
    LCKMGR_SERVER is placed in a hibernate state. If the number of
    active CPUs is increased, the LCKMGR_SERVER resumes servicing
    locking operations.

    Specify one of the following:

    o  Zero (0) indicates that the Dedicated CPU Lock Manager is off
       (the default).

    o  A number greater than zero (0) indicates the number of CPUs
       that must be active before the Dedicated CPU Lock Manager will
       turn on.

    When the Dedicated CPU Lock Manager is turned on, fast path
    devices are not assigned to the CPU used by the Dedicated CPU
    Lock Manager.

    When the Dedicated CPU Lock Manager is turned on, fast path
    devices are not assigned to the CPU used by the Dedicated CPU
    Lock Manager.

    For more information about use of the Dedicated CPU Lock Manager,
    see the OpenVMS Performance Management manual.

    LCKMGR_MODE is a DYNAMIC parameter.

105  –  LGI_BRK_DISUSER

    LGI_BRK_DISUSER turns on the DISUSER flag in the UAF record when
    an attempted break-in is detected, thus permanently locking
    out that account. The parameter is off (0)  by default. You
    should set the parameter (1)  only under extreme security watch
    conditions, because it results in severely restricted user
    service.

    LGI_BRK_DISUSER is a DYNAMIC parameter.

106  –  LGI_BRK_LIM

    LGI_BRK_LIM specifies the number of failures that can occur at
    login time before the system takes action against a possible
    break-in. The count of failures applies independently to login
    attempts by each user name, terminal, and node. Whenever login
    attempts from any of these sources reach the break-in limit
    specified by LGI_BRK_LIM, the system assumes it is under attack
    and initiates evasive action as specified by the LGI_HID_TIM
    parameter.

    The minimum value is 1. The default value is usually adequate.

    LGI_BRK_LIM is a DYNAMIC parameter.

107  –  LGI_BRK_TERM

    LGI_BRK_TERM causes the terminal name to be part of the
    association string for the terminal mode of break-in detection.
    When LGI_BRK_TERM is set to off (0), the processing considers
    the local or remote source of the attempt, allowing break-in
    detection to correlate failed access attempts across multiple
    terminal devices. When set to on (1), LGI_BRK_TERM assumes that
    only local hard-wired or dedicated terminals are in use and
    causes breakin detection processing to include the specific local
    terminal name when examining and correlating break-in attempts.

    Ordinarily, LGI_BRK_TERM should be set to off (0) when physical
    terminal names are created dynamically, such as when network
    protocols like LAT and Telnet are in use.

    LGI_BRK_TERM is a DYNAMIC parameter.

108  –  LGI_BRK_TMO

    LGI_BRK_TMO specifies the length of the failure monitoring
    period. This time increment is added to the suspect's expiration
    time each time a login failure occurs. Once the expiration period
    passes, prior failures are discarded, and the suspect is given a
    clean slate.

    LGI_BRK_TMO is a DYNAMIC parameter.

109  –  LGI_CALLOUTS

    LGI_CALLOUTS specifies the number of installation security policy
    callout modules to be invoked at each login. LGI_CALLOUTS must be
    set to 0 unless callout modules are present.

    LGI_CALLOUTS is a DYNAMIC parameter.

110  –  LGI_HID_TIM

    LGI_HID_TIM specifies the number of seconds that evasive action
    persists following the detection of a possible break-in attempt.
    The system refuses to allow any logins during this period, even
    if a valid user name and password are specified.

    LGI_HID_TIM is a DYNAMIC parameter.

111  –  LGI_PWD_TMO

    LGI_PWD_TMO specifies, in seconds, the period of time a user
    has to enter the correct system password (if used). LGI_PWD_TMO
    also establishes the timeout period for users to enter their
    personal account passwords at login time. Also, when using the
    SET PASSWORD command, LGI_PWD_TMO specifies the period of time
    the system waits for a user to type in a new password, an old
    password, and the password verification.

    LGI_PWD_TMO is a DYNAMIC parameter.

112  –  LGI_RETRY_LIM

    LGI_RETRY_LIM specifies the number of retry attempts allowed
    users attempting to log in. If this parameter is greater than 0,
    and a legitimate user fails to log in correctly because of typing
    errors, the user does not automatically lose the carrier. Instead
    (provided that LGI_RETRY_TMO has not elapsed), by pressing the
    Return key, the user is prompted to enter the user name and
    password again. Once the specified number of attempts has been
    made without success, the user loses the carrier. As long as
    neither LGI_BRK_LIM nor LGI_BRK_TMO has elapsed, the user can
    dial in again and reattempt login.

    LGI_RETRY_LIM is a DYNAMIC parameter.

113  –  LGI_RETRY_TMO

    LGI_RETRY_TMO specifies the number of seconds allowed between
    login retry attempts after each login failure. (Users can
    initiate login retries by pressing the Return key.) This
    parameter is intended to be used with the LGI_RETRY_LIM
    parameter; it allows dialup users a reasonable amount of time
    and number of opportunities to attempt logins before they lose
    the carrier.

    LGI_RETRY_TMO is a DYNAMIC parameter.

114  –  LNMPHASHTBL

    LNMPHASHTBL sets the size of the process logical name hash table.
    Logical names are hashed using a function of the name length
    and contents. The LNMPHASHTBL parameter determines the number
    of entries for process-private logical names. The recommended
    setting is the average number of process-private logical names.
    Note that the hashed values are rounded up to the nearest power
    of 2.

    LNMPHASHTBL has the GEN attribute. On VAX systems, LNMPHASHTBL is
    also an AUTOGEN-altered parameter.

115  –  LNMSHASHTBL

    LNMSHASHTBL sets the size of the system logical name hash table.
    Logical names are hashed using a function of the name length
    and contents. The LNMSHASHTBL parameter determines the number
    of entries for shareable logical names. These names include all
    names from the system, group, and job logical name tables. The
    recommended setting allows one to four logical names per hash
    table entry. The default setting is usually adequate, unless
    your installation has a large number of groups, or many jobs are
    active simultaneously. In that case, an increase in the value of
    the next higher power of 2 might improve logical name translation
    performance. Note that the hashed values are rounded up to the
    nearest power of 2.

    LNMSHASHTBL has the AUTOGEN, FEEDBACK, and GEN attributes.

116  –  LOAD_PWD_POLICY

    LOAD_PWD_POLICY controls whether the SET PASSWORD command
    attempts to use site-specific password policy routines, which
    are contained in the shareable image SYS$LIBRARY:VMS$PASSWORD_
    POLICY.EXE. The default is 0, which indicates not to use policy
    routines.

117  –  LOAD_SYS_IMAGES

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

    LOAD_SYS_IMAGES controls the loading of system images described
    in the system image data file, VMS$SYSTEM_IMAGES. This parameter
    is a bit mask.

    On Alpha and Integrity servers, the following bits are defined:

    Bit                         Description

    0 (SGN$V_LOAD_SYS_IMAGES)   Enables loading alternate execlets
                                specified in VMS$SYSTEM_IMAGES.DATA.

    1 (SGN$V_EXEC_SLICING)      Enables executive slicing.

    2 (SGN$V_RELEASE_PFNS)      Enables releasing unused portions of
                                the Alpha and Integrity servers huge
                                pages.

    These bits are on by default. Using conversational bootstrap exec
    slicing can be disabled.

    On Alpha and Integrity servers, LOAD_SYS_IMAGES is an AUTOGEN
    parameter.

118  –  LOCKDIRWT

    LOCKDIRWT determines the portion of lock manager directory that
    this system handles. The default value is usually adequate.

    LOCKDIRWT is an AUTOGEN parameter.

119  –  LOCKIDTBL

    LOCKIDTBL sets the initial number of entries in the system Lock
    ID table and defines the amount by which the Lock ID table is
    extended whenever the system runs out of locks. One entry must
    exist for each lock in the system; each entry requires 4 bytes.

    For simple timesharing systems, the default value is adequate.
    If your application uses many locks, as in the case of heavy RMS
    file sharing or a database management application, you should
    increase this parameter. When you change the value of LOCKIDTBL,
    examine the value of RESHASHTBL and change it if necessary.

    The OpenVMS Lock Management facility is described in the VSI
    OpenVMS Programming Concepts Manual. You can monitor locks with
    the MONITOR LOCK command of the Monitor utility.

    LOCKIDTBL has the AUTOGEN, FEEDBACK, and MAJOR attributes.

120  –  LOCKIDTBL_MAX

    LOCKIDTBL_MAX is obsolete beginning with OpenVMS Version 7.1.

121  –  LOCKRETRY

    LOCKRETRY establishes the number of attempts made to lock a
    multiprocessor data structure.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

122  –  LOCKRMWT

                                   NOTE

       On OpenVMS Version 8.3 systems, LOCKRMWT does not control
       lock remastering. See LOCKDIRWT.

    LOCKRMWT can have a value from zero to 10. The default is 5.
    Remaster decisions are based on the difference in lock remaster
    weights between the master and a remote node. When weights are
    equal, the remote node needs about 13% more activity before the
    tree is remastered. If a remote node has a higher lock remaster
    weight, the amount of activity is less. If the remote node has a
    lower lock remaster weight, the additional activity required to
    move the tree is much greater.

    Lock remaster weights of zero and 10 have additional meanings.
    A value of zero indicates that a node does not want to master
    trees and always remasters to an interested node with a higher
    LOCKRMWT. Lock trees on an interested node with a LOCKRMWT
    lower than 10 are remastered to the node with a weight of 10
    for LOCKRMWT.

    LOCKRMWT is a DYNAMIC parameter.

123  –  LONGWAIT

    LONGWAIT defines how much real time (in seconds) must elapse
    before the swapper considers a process to be temporarily idle.
    This parameter is applied to local event flag (LEF) and hibernate
    (HIB) waits to detect such conditions as an inactive terminal or
    ACP.

    LONGWAIT has the DYNAMIC, GEN, and MAJOR attributes. On Alpha
    and Integrity servers, LONGWAIT is also an AUTOGEN-altered
    parameter.

124  –  MAXBOBMEM

    (Alpha and Integrity servers) MAXBOBMEM defines the maximum
    amount of physical memory, measured in pagelets, that can be
    associated with a single buffer object created by a process
    in user mode. The default value of 0 means there is no system-
    imposed limit on the size of a buffer object.

    MAXBOBMEM is a DYNAMIC parameter.

    Other MAXBOB* parameters are obsolete beginning with OpenVMS
    Version 7.3.

125  –  MAXBUF

    MAXBUF sets the maximum allowable size for any single buffered
    I/O packet. Buffered I/O packets are allocated from the
    permanently resident nonpaged dynamic pool. The terminal,
    mailbox, and printer device drivers are examples of device
    drivers that perform buffered I/O.

    The number of bytes specified in the I/O request plus the size of
    a driver-dependent and function-dependent header area determine
    the required buffered I/O packet size. The size of the header
    area is a minimum of 16 bytes; there is no absolute upper limit.
    However, this header area is usually a few hundred bytes in size.

    The default value on Alpha and Integrity servers continues to be
    8192.

    The maximum value of MAXBUF is 64000 bytes.

    MAXBUF is a DYNAMIC parameter.

126  –  MAXCLASSPRI

    If class scheduling is enabled, MAXCLASSPRI sets the maximum
    range in the priority range of class-scheduled processes.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

    MAXCLASSPRI is a DYNAMIC parameter.

127  –  MAXPROCESSCNT

    MAXPROCESSCNT sets the number of process entry slots allocated at
    bootstrap time. One slot is required for each concurrent process
    on the system. Each slot requires 6 bytes of permanently resident
    memory.

    The default value is normally configured to allow you to create
    the desired number of processes. If the following message
    appears, you need to increase the value of MAXPROCESSCNT:

    %SYSTEM-F-NOSLOT,  No PCB to create process

    On Alpha and Integrity servers beginning with Version 8.1, the
    default value is 32,767.

    MAXPROCESSCNT has the AUTOGEN, FEEDBACK, GEN, and MAJOR
    attributes.

128  –  MAXQUEPRI

    MAXQUEPRI determines the highest scheduling priority that can be
    assigned to jobs entered in batch and output (printer, server,
    and terminal) queues without the submitter process having OPER or
    ALTPRI privilege. The value of this parameter can range from 0 to
    255; the default is 100. The value of MAXQUEPRI should be greater
    than or equal to DEFQUEPRI.

                                   NOTE

       MAXQUEPRI refers to relative queue scheduling priority, not
       to the execution priority of the job.

    MAXQUEPRI is a DYNAMIC parameter.

129  –  MAXSYSGROUP

    MAXSYSGROUP sets the highest value that a group number can have
    and still be classified as a system UIC group number. Note that
    the specification is not in octal unless preceded by the %O radix
    indicator. This parameter is normally left at 8 (10 octal).

    MAXSYSGROUP is a DYNAMIC parameter.

130  –  MC_SERVICES_P0

    (Alpha only) MC_SERVICES_P0 controls whether other MEMORY CHANNEL
    nodes in the cluster continue to run if this node bugchecks or
    shuts down.

    A value of 1 causes other nodes in the MEMORY CHANNEL cluster to
    crash with bugcheck code MC_FORCED_CRASH if this node bugchecks
    or shuts down.

    The default value is 0. A setting of 1 is intended only for
    debugging purposes; the parameter should otherwise be left at
    its default value.

    MC_SERVICES_P0 is a DYNAMIC parameter.

131  –  MC_SERVICES_P1

    (Alpha only) This special parameter is reserved for VSI use. Its
    value must be the same on all nodes connected by MEMORY CHANNEL.

    MC_SERVICES_P1 is a DYNAMIC parameter.

132  –  MC_SERVICES_P2

    (Alpha only) MC_SERVICES_P2 specifies whether to load the
    PMDRIVER (PMA0) MEMORY CHANNEL cluster port driver.

    PMDRIVER is a driver that serves as the MEMORY CHANNEL cluster
    port driver. It works together with MCDRIVER (the MEMORY CHANNEL
    device driver and driver interface) to provide MEMORY CHANNEL
    clustering. If PMDRIVER is not loaded, cluster connections are
    not made over the MEMORY CHANNEL interconnect.

    The default value is 1, which causes PMDRIVER to be loaded when
    you boot the system. When you run CLUSTER_CONFIG.COM and select
    the MEMORY CHANNEL option, PMDRIVER is loaded automatically when
    you reboot the system.

    VSI recommends that this value not be changed. This parameter
    value must be the same on all nodes connected by MEMORY CHANNEL.

133  –  MC_SERVICES_P3

    (Alpha only) MC_SERVICES_P3 specifies the maximum number of tags
    supported. The maximum value is 2048, and the minimum value is
    100.

    The default value is 800. VSI recommends that this value not
    be changed. This parameter value must be the same on all nodes
    connected by MEMORY CHANNEL.

    MC_SERVICES_P3 is a DYNAMIC parameter.

134  –  MC_SERVICES_P4

    (Alpha only) MC_SERVICES_P4 specifies the maximum number of
    regions supported. The maximum value is 4096, and the minimum
    value is 100.

    The default value is 200. VSI recommends that this value not
    be changed. This parameter value must be the same on all nodes
    connected by MEMORY CHANNEL.

135  –  MC_SERVICES_P5

    (Alpha only) MC_SERVICES_P5 is reserved for VSI use only and must
    remain at the default value of 8000000. This value must be the
    same on all nodes connected by MEMORY CHANNEL.

    MC_SERVICES_P5 is a DYNAMIC parameter.

136  –  MC_SERVICES_P6

    (Alpha only) MC_SERVICES_P6 specifies MEMORY CHANNEL message
    size, the body of an entry in a free queue, or a work queue. The
    maximum value is 65536, and the minimum value is 544.

    The default value is 992. This value is suitable in all cases
    except for systems with highly constrained memory. For such
    systems, you can reduce the memory consumptions of MEMORY CHANNEL
    by slightly reducing the default value of 992. The value of MC_
    SERVICES_P6 must always be equal to or greater than the result of
    the following calculations:

    1. Select the larger of SCS_MAXMSG and SCS_MAXDG.

    2. Round that value up to the next quadword.

    The value of MC_SERVICES_P6 must be the same on all nodes
    connected by MEMORY CHANNEL.

137  –  MC_SERVICES_P7

    (Alpha only) MC_SERVICES_P7 specifies whether to suppress or
    display messages about MEMORY CHANNEL activities on this node.
    This parameter can be set to a value of 0, 1, or 2:

    o  A value of 0 indicates nonverbose mode: no informational
       messages appear on the console or in the error log.

    o  A value of 1 indicates verbose mode: informational messages
       from both MCDRIVER and PMDRIVER appear on the console and in
       the error log.

    o  A value of 2 provides the same output as a value of 1, with
       the addition of PMDRIVER stalling and recovery messages.

    The default value is 0. VSI recommends that this value not
    be changed except while debugging MEMORY CHANNEL problems or
    adjusting the MC_SERVICES_P9 parameter.

    MC_SERVICES_P7 is a DYNAMIC parameter.

138  –  MC_SERVICES_P8

    (Alpha only) MC_SERVICES_P8 is reserved for VSI use only and must
    remain at the default value of 0. The value must be the same on
    all nodes connected by MEMORY CHANNEL.

139  –  MC_SERVICES_P9

    (Alpha only) MC_SERVICES_P9 specifies the number of initial
    entries in a single channel's free queue. The maximum value is
    2048, and the minimum value is 10.

    Note that MC_SERVICES_P9 is not a dynamic parameter; you must
    reboot the system after each change for that change to take
    effect.

    The default value is 150. VSI recommends that this value not be
    changed.

    The value of MC_SERVICES_P9 must be the same on all nodes
    connected by MEMORY CHANNEL.

140  –  MINCLASSPRI

    If class scheduling is enabled, MINCLASSPRI sets the minimum
    range in the priority range of class-scheduled processes.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

    MINCLASSPRI is a DYNAMIC parameter.

141  –  MINWSCNT

    The value specified by MINWSCNT is added to the size of the
    process header to establish the minimum working set size.

    On Alpha and Integrity servers, MINWSCNT sets the minimum number
    of pages required for the execution of a process. The default
    value is 20; the minimum value is 10.

    MINWSCNT is an AUTOGEN parameter.

142  –  MMG_CTLFLAGS

    MMG_CTLFLAGS is a bitmask used to enable or disable memory
    management-related activities.

    The first two bits, 0 and 1, control the proactive memory
    reclamation mechanisms. Bit 2 controls deferred memory testing.

    The following bit mask values are defined:

    Bit    Description

    0      If this bit is set, reclamation is enabled by trimming
           from periodically executing, but otherwise idle,
           processes. This occurs when the size of the free list
           plus the modified list drops below two times the value of
           FREEGOAL. This function is disabled if the bit is clear.

    1      If this bit is set, reclamation is enabled by outswapping
           processes that have been idle for longer than LONGWAIT
           seconds. This occurs when the size of the free list drops
           below FREEGOAL. This function is disabled if the bit is
           clear.

    2      Controls deferred memory testing (only on AlphaServer
           4100 systems). You can use this bit to speed up elapsed
           bootstrap time by controlling when memory is tested:

           o  If the bit is clear (the default), OpenVMS tests memory
              as a background activity, which might or might not
              complete before the end of the bootstrap process.

           o  If the bit is set, all memory is tested in the
              bootstrap process by the end of the EXEC_INIT phase
              (that is, before IPL is lowered from 31).

    3      Reserved to OpenVMS use; must be zero.

    4      If this bit is clear (the default), all page sizes
           supported by hardware can be used to map resident memory
           sections on Integrity servers. If this bit is set, page
           sizes on Integrity servers are limited to the maximum
           GH factor available on Alpha systems (512 * <system page
           size>).

    5-7    Reserved for future use.

    MMG_CTLFLAGS is an AUTOGEN and DYNAMIC parameter.

143  –  MOUNTMSG_(D)

    MOUNTMSG controls whether or not the messages that log volume
    mounts appear on the operator's terminal and in the operator's
    log. The default value of 0 disables reporting of these messages.
    This parameter does not control the messages generated by mount
    assistance requests.

    MOUNTMSG is a DYNAMIC parameter.

144  –  MPDEV_AFB_INTVL

    (Alpha and Integrity servers) MPDEV_AFB_INTVL specifies the
    automatic failback interval in seconds. The automatic failback
    interval is the minimum number of seconds that must elapse before
    the system attempts another failback from an MSCP path to a
    direct path on the same device.

    MPDEV_POLLER must be set to ON to enable automatic failback. You
    can disable automatic failback without disabling the poller by
    setting MPDEV_AFB_INTVL to 0. The default is 300 seconds.

145  –  MPDEV_D*

    (Alpha and Integrity servers) MPDEV_D1 through MPDEV_D4 are
    reserved for use by the operating system.

146  –  MPDEV_ENABLE

    (Alpha and Integrity servers) MPDEV_ENABLE enables the formation
    of multipath sets when set to ON (1).  If MPDEV_ENABLE is set
    to OFF (0),  the formation of additional multipath sets and the
    addition of new paths to existing multipath sets are disabled.
    However, existing multipath sets remain in effect. The default is
    ON.

    MPDEV_REMOTE and MPDEV_AFB_INTVL have no effect when MPDEV_ENABLE
    is set to OFF.

147  –  MPDEV_LCRETRIES

    (Alpha and Integrity servers) MPDEV_LCRETRIES controls the number
    of times the system retries the direct paths to the controller
    that the logical unit is online to, before moving on to direct
    paths to the other controller, or to an MSCP served path to the
    device. The valid range for retries is 1 through 256. The default
    is 1.

148  –  MPDEV_POLLER

    (Alpha and Integrity servers) MPDEV_POLLER enables polling of
    the paths to multipath set members when set to ON (1).  Polling
    allows early detection of errors on inactive paths. If a path
    becomes unavailable or returns to service, the system manager is
    notified with an OPCOM message. When set to OFF (0),  multipath
    polling is disabled. The default is ON. Note that this parameter
    must be set to ON to use the automatic failback feature.

149  –  MPDEV_REMOTE

    (Alpha and Integrity servers) MPDEV_REMOTE enables MSCP served
    paths to become members of a multipath set when set to ON (1).
    When set to OFF (0),  only local paths to a SCSI or Fibre Channel
    device is used in the formation of additional multipath sets.
    However, setting this parameter to OFF does not have any effect
    on existing multipath sets that have remote paths.

    To use multipath failover to a served path, MPDEV_REMOTE must
    be enabled on all systems that have direct access to shared
    SCSI/Fibre Channel devices. The first release to provide this
    feature is OpenVMS Alpha Version 7.3-1. Therefore, all nodes
    on which MPDEV_REMOTE is enabled must be running OpenVMS Alpha
    Version 7.3-1 (or later).

    If MPDEV_ENABLE is set to OFF (0), the setting of MPDEV_REMOTE
    has no effect because the addition of all new paths to multipath
    sets is disabled. The default is ON.

150  –  MPW_HILIMIT

    MPW_HILIMIT sets an upper limit for the modified-page list. When
    the list accumulates the number of pages specified by this limit,
    writing of the list begins. The pages that are written are then
    transferred to the free-page list.

    If MPW_HILIMIT is too low, excessive page faulting can occur from
    the page file. If it is too high, too many physical pages can be
    consumed by the modified-page list.

    If you increase MPW_HILIMIT, you might also need to increase
    MPW_WAITLIMIT. Note that if MPW_WAITLIMIT is less than
    MPW_HILIMIT, a system deadlock occurs. The values for the two
    parameters are usually equal.

    MPW_HILIMIT has the AUTOGEN and GEN attributes.

151  –  MPW_IOLIMIT

    MPW_IOLIMIT specifies the number of outstanding I/Os to the
    modified-page writer.

    On Alpha and Integrity servers, MPW_IOLIMIT is an AUTOGEN-altered
    parameter.

152  –  MPW_LOLIMIT

    MPW_LOLIMIT sets a lower limit for the modified-page list. When
    writing of the list causes the number of pages on the list to
    drop to or below this limit, writing stops.

    MPW_LOLIMIT ensures that a certain number of pages are available
    on the modified-page list for page faults. If the number is
    too small, the caching effectiveness of the modified-page list
    is reduced. If it is too high, less memory is available for
    processes, so that swap (and page) may increase.

    MPW_LOLIMIT has the AUTOGEN and GEN attributes.

153  –  MPW_LOWAITLIMIT

    MPW_LOWAITLIMIT specifies the threshold at which processes in
    the miscellaneous wait state MPWBUSY are allowed to resume.
    MPW_LOWAITLIMIT increases system performance for fast processors
    with large memories by reducing the amount of time processes
    spend in the MPWBUSY wait state.

    MPW_LOWAITLIMIT has the AUTOGEN and DYNAMIC attributes.

154  –  MPW_PRIO

    MPW_PRIO sets the priority of I/O transfers initiated by the
    modified page writer. The maximum value is 31, the minimum is 0,
    and the default is 4.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

155  –  MPW_THRESH

    MPW_THRESH sets a lower bound of pages that must exist on the
    modified-page list before the swapper writes this list to acquire
    free pages. If this requirement is met, the swapper tries to
    write the modified-page list rather than taking pages away from
    or swapping out a process.

    MPW_THRESH has the DYNAMIC attribute. On Alpha and Integrity
    servers, MPW_THRESH is also an AUTOGEN parameter.

156  –  MPW_WAITLIMIT

    MPW_WAITLIMIT sets the number of pages on the modified-page list
    that causes a process to wait until the next time the modified-
    page writer writes the modified list. This parameter limits the
    rate at which any single process can produce modified pages. If
    this value is less than MPW_HILIMIT, a system deadlock occurs.
    The value for this parameter is normally equal to MPW_HILIMIT.

    MPW_WAITLIMIT has the AUTOGEN and DYNAMIC attributes.

157  –  MPW_WRTCLUSTER

    MPW_WRTCLUSTER sets the number of pages to be written during one
    I/O operation from the modified-page list to the page file or
    a section file. The actual size of the cluster may be limited
    by the number of pages available for the I/O operation. This
    parameter can range in value from 16 to 120, in multiples of 8.
    Each page in the cluster requires 6 bytes of permanently resident
    memory.

    If MPW_WRTCLUSTER is too small, it takes many I/O operations
    to empty the modified-page list. If MPW_WRTCLUSTER is too large
    for the speed of the disk that holds the page file, other I/O
    operations are held up for the modified-page list write.

    On Alpha and Integrity servers, the MPW_WRTCLUSTER default value
    is 64 8192-byte pages; its maximum value is 512 8192-byte pages;
    and its minimum value is 16 8192-byte pages.

    MPW_WRTCLUSTER has the AUTOGEN and GEN attributes.

158  –  MSCP_BUFFER

    This buffer area is the space used by the server to transfer data
    between client systems and local disks.

    On Alpha and Integrity servers, MSCP_BUFFER specifies the number
    of pagelets to be allocated to the MSCP server's local buffer
    area.

    MSCP_BUFFER is an AUTOGEN and FEEDBACK parameter.

159  –  MSCP_CMD_TMO

    MSCP_CMD_TMO is the time in seconds that the OpenVMS MSCP server
    uses to detect MSCP command timeouts. The MSCP Server must
    complete the command within a built-in time of approximately
    40 seconds plus the value of the MSCP_CMD_TMO parameter.

    The MSCP_CMD_TMO default value of 0 is normally adequate. A
    value of 0 provides the same behavior as in previous releases
    of OpenVMS (which did not have an MSCP_CMD_TMO system parameter).
    A nonzero setting increases the amount of time before an MSCP
    command times out.

    If command timeout errors are being logged on client nodes,
    setting the parameter to a nonzero value on OpenVMS servers
    may reduce the number of errors logged. As the value of the
    MSCP_CMD_TMO increases, the number of client MSCP command timeouts
    will decrease, at the cost of increased time to detect a faulty
    MSCP controller or MSCP-served device.

    If you need to decrease the number of command timeout errors, VSI
    recommends that you set an initial value of 60. If timeout errors
    continue to be logged, you can increase this value in increments
    of 20 seconds.

    MSCP_CMD_TMO is a DYNAMIC parameter.

160  –  MSCP_CREDITS

    MSCP_CREDITS specifies the number of outstanding I/O requests
    that can be active from one client system.

    The default value is currently 32. Unless a system has very
    constrained memory available, VSI recommends that these values
    not be increased.

161  –  MSCP_LOAD

    MSCP_LOAD controls the loading of the MSCP server during a system
    boot. Specify one of the following values:

    Value  Description

    0      Do not load the MSCP server. This is the default value.

    1      Load the MSCP server and serve disks as specified by the
           MSCP_SERVE_ALL parameter.

    MSCP_LOAD has the AUTOGEN attribute.

162  –  MSCP_SERVE_ALL

    MSCP_SERVE_ALL is a bit mask that controls disk serving in an
    OpenVMS Cluster. A disk is served regardless of its allocation
    class unless bit 3 has a value of 1.

    Starting with OpenVMS Version 7.2, the serving types are
    implemented as a bit mask. To specify the type of serving your
    system will perform, locate the type you want in the following
    table and specify its value. For some systems, you may want to
    specify two serving types, such as serving the system disk and
    serving locally attached disks. To specify such a combination,
    add the values of each type, and specify the sum.

    In a mixed-version cluster that includes any systems running
    OpenVMS Version 7.1-x or earlier, serving all available disks
    is restricted to serving all disks except those whose allocation
    class does not match the system's node allocation class (prior
    to Version 7.2). To specify this type of serving, use the value 9
    (which sets bit 0 and bit 3).

    The following table describes the serving type controlled by each
    bit and its decimal value:

    Bit and
    Value
    When Set      Description

    Bit 0 (1)     Serve all available disks (locally attached and
                  those connected to HSx and DSSI controllers).
                  Disks with allocation classes that differ from
                  the system's allocation class (set by the ALLOCLASS
                  parameter) are also served if bit 3 is not set.

    Bit 1 (2)     Serve locally attached (non-HSx and DSSI) disks.

    Bit 2 (4)     Serve the system disk. This is the default setting.
                  This setting is important when other nodes in the
                  cluster rely on this system being able to serve
                  its system disk. This setting prevents obscure
                  contention problems that can occur when a system
                  attempts to complete I/O to a remote system disk
                  whose system has failed.

    Bit 3 (8)     Restrict the serving specified by bit 0. All disks
                  except those with allocation classes that differ
                  from the system's allocation class (set by the
                  ALLOCLASS parameter) are served.

                  This is pre-Version 7.2 behavior. If your cluster
                  includes systems running OpenVMS 7.1-x or earlier,
                  and you want to serve all available disks, you must
                  specify 9, the result of setting this bit and bit
                  0.

    Although the serving types are now implemented as a bit mask, the
    values of 0, 1, and 2, specified by bit 0 and bit 1, retain their
    original meanings:

       0 - Do not serve any disks (the default for earlier versions
       of OpenVMS).

       1 - Serve all available disks.

       2 - Serve only locally attached (non-HSx and non-DSSI) disks.

    If the MSCP_LOAD system parameter is 0, MSCP_SERVE_ALL is
    ignored.

163  –  MULTIPROCESSING

    MULTIPROCESSING controls the loading of the system
    synchronization image.

    Specify one of the following values:

    Value    Description

    0        Load the uniprocessing synchronization image
             SYSTEM_SYNCHRONIZATION_UNI.EXE.

    1        If the CPU type is capable of SMP and two or
             more CPUs are present on the system, load the
             full-checking multiprocessing synchronization
             image SYSTEM_SYNCHRONIZATION.EXE. Otherwise,
             load the uniprocessing synchronization image
             SYSTEM_SYNCHRONIZATION_UNI.EXE.

    2        Always load the full-checking version
             SYSTEM_SYNCHRONIZATION.EXE, regardless of system
             configuration or CPU availability.

    3        If the CPU type is capable of SMP and two or more
             CPUs are present on the system, load the optimized
             streamlined multiprocessing image:

             o  On Alpha and Integrity servers, this image is
                SYSTEM_SYNCHRONIZATION_MIN.EXE.

             Otherwise, load the uniprocessing synchronization image
             SYSTEM_SYNCHRONIZATION_UNI.EXE. The default value is 3.

    4        Always load the streamlined multiprocessing image
             SYSTEM_SYNCHRONIZATION_MIN.EXE, regardless of system
             configuration or CPU availability.

    Setting the SYSTEM_CHECK parameter to 1 has the effect of setting
    MULTIPROCESSING to 2.

164  –  MULTITHREAD

    MULTITHREAD controls the availability of kernel threads
    functions. Specify one of the following values:

    Value            Description

    0                Both Thread Manager upcalls and the creation of
                     multiple kernel threads are disabled.

    1                Thread Manager upcalls are enabled; the creation
                     of multiple kernel threads is disabled.

    2-256 (Alpha     Both Thread Manager upcalls and the creation
    and Integrity    of multiple kernel threads are enabled. The
    servers)         number specified represents the maximum number
                     of kernel threads that can be created for a
                     single process.

    The maximum value for MULTITHREAD is 256.

    MULTITHREAD is an AUTOGEN and DYNAMIC parameter.

165  –  MVSUPMSG_INTVL

    (Alpha and Integrity servers) The system suppresses mount
    verification start and end messages for fibre channel disk
    devices if mount verification completes on the first attempt
    and if mount verification does not occur too often. MVSUPMSG_NUM
    and this parameter establish this limit.

    The system issues a mount verification message after a sequence
    of MVSUPMSG_NUM mount verifications have gone unannounced on a
    specific fibre channel disk device within a span of MVSUPMSG_
    INTVL seconds.

    If this parameter is zero, all mount verification messages are
    announced.

    MVSUPMSG_INTVL is a DYNAMIC parameter.

166  –  MVSUPMSG_NUM

    (Alpha and Integrity servers) The system suppresses mount
    verification start and end messages for fibre channel disk
    devices if mount verification completes on the first attempt and
    if mount verification does not occur too often. MVSUPMSG_INTVL
    and this parameter establish this limit.

    The system issues a mount verification message after a sequence
    of MVSUPMSG_NUM mount verifications have gone unannounced on a
    specific fibre channel disk device within a span of MVSUPMSG_
    INTVL seconds.

    If this parameter is zero, all mount verification messages are
    announced.

    MVSUPMSG_NUM is a DYNAMIC parameter.

167  –  MVTIMEOUT

    MVTIMEOUT is the time in seconds that a mount verification
    attempt continues on a given disk volume. If the mount
    verification does not recover the volume within that time, the
    I/O operations outstanding to the volume terminate abnormally.

    MVTIMEOUT is a DYNAMIC parameter. On Alpha and Integrity servers,
    MVTIMEOUT is also an AUTOGEN parameter.

168  –  NET_CALLOUTS

    NET_CALLOUTS is normally set to 0. A value of 255 indicates that
    no attempt is to be made to assign a new proxy connection to an
    active server, but that a new process must be started to invoke
    the installation security policy callout modules in LOGINOUT.EXE.
    Values 1 through 254 are reserved for future use.

    NET_CALLOUTS is a DYNAMIC parameter.

169  –  NISCS_CONV_BOOT

    NISCS_CONV_BOOT controls whether a conversational boot is
    permitted during a remote system boot. The default value of 0
    specifies that conversational boots are not permitted.

170  –  NISCS_LOAD_PEA0

    NISCS_LOAD_PEA0 controls whether the NI-SCS port driver PEDRIVER
    is loaded during system boot. The default of 0 specifies that the
    PEDRIVER is not loaded.

171  –  NISCS_MAX_PKTSZ

    This parameter specifies an upper limit on the size, in bytes,
    of the user data area in the largest packet sent by NISCA on any
    local area network (LAN).

    NISCS_MAX_PKTSZ allows the system manager to change the packet
    size used for cluster communications on network communication
    paths. PEDRIVER automatically allocates memory to support
    the largest packet size that is usable by any virtual circuit
    connected to the system up to the limit set by this parameter. On
    Alpha and Integrity servers, to optimize performance, the default
    value is the largest packet size currently supported by OpenVMS.

    PEDRIVER uses NISCS_MAX_PKTSZ to compute the maximum amount of
    data to transmit in any LAN packet:

    LAN packet size <= LAN header (padded Ethernet format)
                       + NISCS_MAX_PKTSZ
                       + NISCS checksum (only if data checking
                                         is enabled)
                       + LAN CRC or FCS

    The actual packet size automatically used by PEDRIVER might be
    smaller than the NISCS_MAX_PKTSZ limit for any of the following
    reasons:

    o  On a per-LAN path basis, if PEdriver determines that the LAN
       path between two nodes, including the local and remote LAN
       adapters and intervening LAN equipment, can only convey a
       lesser size.

       In other words, only nodes with large-packet LAN adapters
       connected end-to-end by large-packet LAN equipment can use
       large packets. Nodes connected to large-packet LANs but having
       an end-to-end path that involves an Ethernet segment restrict
       packet size to that of an Ethernet packet (1498 bytes).

    o  For performance reasons, PEDRIVER might further limit
       the upper bound on packet size so that the packets can be
       allocated from a lookaside list in the nonpaged pool.

    The actual memory allocation includes the required data structure
    overhead used by PEDRIVER and the LAN drivers, in addition to the
    actual LAN packet size.

    The following table shows the minimum NISCS_MAX_PKTSZ value
    required to use the maximum packet size supported by specified
    LAN types:

    Type of LAN           Minimum Value for NISCS_MAX_PKTSZ

    Ethernet              1498

    FDDI                  4382 (before Version 7.3)
                          4396 (Version 7.3 and later)

    Gigabit Ethernet      8192

    ATM                   7606

    Note that the maximum packet size for some Gigabit Ethernet
    adapters is larger than the maximum value of NISCS_MAX_PKTSZ
    (8192 bytes). See the LAN_FLAGS parameter for a description of
    how to enable jumbo frames on Gigabit Ethernet-that is, packet
    sizes larger than those noted for Ethernet.

    On Alpha and Integrity servers, NISCS_MAX_PKTSZ is an AUTOGEN
    parameter.

172  –  NISCS_PORT_SERV

    NISCS_PORT_SERV provides flag bits for PEDRIVER port services:

    o  Setting bits 0 and 1 (hex bitmask value 3) enables data
       checking.

    o  Setting bit 2 (hex bitmask value 4) enables data compression
       on all virtual channels (VCs) to nodes that support
       compression.

    The remaining bits are reserved for future use.

    Starting with OpenVMS Version 7.3-1, you can use the SCACP
    command SET VC/CHECKSUMMING to specify data checking on the VCs
    to certain nodes. You can do this on a running system. (For more
    information, see the SCACP documentation in the VSI OpenVMS System
    Management Utilities Reference Manual.

    Starting with OpenVMS Version 8.3, you can also use the SCACP
    command SET VC/COMPRESSION to specify data compression on the
    on the VCs to certain nodes. You can use SCACP to enable either
    data checking or data compression on a running system. (See the
    SCACP documentation in the the VSI OpenVMS System Management
    Utilities Reference Manual for more information. Also starting
    with OpenVMS Version 8.3, the NISCS_PORT_SERV system parameter
    is dynamic, that is, changing the setting of this parameter no
    longer requires a reboot. Furthermore, this parameter applies
    to all virtual circuits between the node on which it is set and
    other nodes in the cluster.

    NISCS_PORT_SERV has the DYNAMIC and AUTOGEN attributes.

173  –  NOAUTOCONFIG

    NOAUTOCONFIG controls whether all devices are automatically
    configured when the system boots. The default value of 0 sets the
    system to automatically configure all devices. Set NOAUTOCONFIG
    to 1 (no automatic configuration) only for debugging purposes.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

    NOAUTOCONFIG is a DYNAMIC parameter.

174  –  NOCLUSTER

    NOCLUSTER controls whether page read clustering is inhibited
    when the system boots. Set NOCLUSTER to 1 (inhibit page read
    clustering) only for debugging purposes.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

175  –  NOPGFLSWP

    If enabled, NOPGFLSWP disables swapping into page files.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

176  –  NPAGECALC

    NPAGECALC controls whether the system automatically calculates
    the initial size for nonpaged dynamic memory.

    VSI sets the default value of NPAGECALC to 1 only during the
    initial boot after an installation or upgrade. When the value
    of NPAGECALC is 1, the system calculates an initial value for the
    NPAGEVIR and NPAGEDYN system parameters. This calculated value is
    based on the amount of physical memory in the system.

    NPAGECALC's calculations do not reduce the values of NPAGEVIR and
    NPAGEDYN from the values you see or set at the SYSBOOT prompt.
    However, NPAGECALC's calculation might increase these values.

    AUTOGEN sets NPAGECALC to 0. NPAGECALC should always remain 0
    after AUTOGEN has determined more refined values for the NPAGEDYN
    and NPAGEVIR system parameters.

177  –  NPAGEDYN

    NPAGEDYN sets the size of the nonpaged dynamic pool in bytes.
    This figure is rounded down to an integral number of pages.
    NPAGEDYN establishes the initial setting of the nonpaged pool
    size, but the pool size can be increased dynamically.

    To set a value for this parameter, use AUTOGEN initially, and
    then monitor the amount of space actually used with the DCL
    command SHOW MEMORY/POOL/FULL.

    For the benefit of OpenVMS VAX systems with limited physical
    memory, AUTOGEN logs a warning message in its report if NPAGEDYN
    exceeds 10 percent of physical memory or if NPAGEVIR exceeds 33
    percent of physical memory.

    AUTOGEN also limits its own calculated value for NPAGEDYN to
    20 percent of physical memory and limits NPAGEVIR to 50 percent
    of physical memory. These calculated values are adequate for
    most workstations and systems with 16 or fewer megabytes of
    physical memory. If your system requires a larger value, you can
    override the AUTOGEN calculated values by setting higher values
    in MODPARAMS.DAT.

    NPAGEDYN has AUTOGEN, FEEDBACK, GEN, and MAJOR attributes.

178  –  NPAGERAD

    (Alpha and Integrity servers) NPAGERAD specifies the total number
    of bytes of nonpaged pool that will be allocated for Resource
    Affinity Domains (RADs) other than the base RAD. For platforms
    that have no RADs, NPAGERAD is ignored. Notice that NPAGEDYN
    specifies the total amount of nonpaged pool for all RADs.

    Also notice that the OpenVMS system might round the specified
    values higher to an even number of pages for each RAD, which
    prevents the base RAD from having too little nonpaged pool. For
    example, if the hardware is an AlphaServer GS160 with 4 RADs:

    NPAGEDYN = 6291456 bytes
    NPAGERAD = 2097152 bytes

    In this case, the OpenVMS system allocates a total of
    approximately 6,291,456 bytes of nonpaged pool. Of this amount,
    the system divides 2,097,152 bytes among the RADs that are not
    the base RAD. The system then assigns the remaining 4,194,304
    bytes to the base RAD.

                                   NOTE

       The system actually rounds up to an even number of pages
       on each RAD. In addition, the base RAD is never assigned a
       value less than the smaller of the value of NPAGEDYN and 4
       megabytes.

    On AlphaServer GS series processors on OpenVMS systems prior to
    Version 7.3-1, system managers frequently saw pool expansion that
    increasing NPAGEDYN did not reduce. This problem was caused by
    leaving NPAGERAD at its default value of 0.

    Starting with OpenVMS Version 7.3-1, when NPAGERAD is 0 (the
    default), the system calculates a value to use for NPAGERAD with
    the following formula:

                      Base RAD memory
       NPAGEDYN * (1- --------------- )
                       Total memory

    This calculation gives more pool to the non-base RADs than before
    and, therefore, reduces the expansion of non-base RADs.

    NPAGERAD has the GEN attribute.

179  –  NPAGEVIR

    NPAGEVIR defines the maximum size to which NPAGEDYN can be
    increased. If this value is too small, the system can hang.
    If NPAGEVIR is too large, the result is a penalty of 4 bytes
    per extra page on VAX and 8 bytes per extra page on Alpha and
    Integrity servers.

    For the benefit of OpenVMS VAX systems with limited physical
    memory, AUTOGEN logs a warning message in its report if NPAGEDYN
    exceeds 10 percent of physical memory or if NPAGEVIR exceeds 33
    percent of physical memory.

    AUTOGEN also limits its own calculated value for NPAGEDYN to 20
    percent of physical memory, and limits NPAGEVIR to 50 percent
    of physical memory. These calculated values are adequate for
    most workstations and systems with 16 or fewer megabytes of
    physical memory. If your system requires a larger value, you can
    override the AUTOGEN calculated values by setting higher values
    in MODPARAMS.DAT.

    NPAGEVIR has AUTOGEN and GEN attributes.

180  –  NPAG_AGGRESSIVE

    Beginning with OpenVMS Version 8.2, the default values of NPAG_
    AGGRESSIVE and NPAG_GENTLE are 100. A value of 100 turns off
    both gentle and aggressive reclamation of nonpaged pool lookaside
    lists. In many cases, when pool reclamation moves small packets
    from the lookaside lists back to the variable list, the result
    is fragmentation of the variable list. This fragmentation appears
    as many small packets at the front of the variable list and a few
    large packets at the end of the list.

    When an allocation occurs for a packet that is larger than any
    of the lookaside lists, the system must find a large enough
    packet on the variable list. When heavily fragmented, the entire
    variable list often must be searched to find a large enough
    packet. Because the variable list is kept in address order, when
    a large packet is deallocated, the entire list must be searched
    again to deallocate the packet.

    Under these conditions, system performance can be severely
    degraded. For this reason, VSI recommends that you turn off pool
    reclamation but keep both NPAG_AGGRESSIVE and NPAG_GENTLE system
    parameters set to 100.

    NPAG_AGGRESSIVE is a DYNAMIC parameter.

181  –  NPAG_BAP_MAX

    (Alpha and Integrity servers) NPAG_BAP_MAX is the size in bytes
    of the bus addressable pool (BAP) that the system creates under
    normal circumstances.

    See also NPAG_BAP_MIN.

182  –  NPAG_BAP_MAX_PA

    (Alpha and Integrity servers) NPAG_BAP_MAX_PA is the highest
    physical address in megabytes that is allowed in bus addressable
    pool (BAP).

183  –  NPAG_BAP_MIN

    (Alpha and Integrity servers) NPAG_BAP_MIN is the size in bytes
    of the bus addressable pool (BAP) that the system creates when
    memory resources are unusually constrained.

184  –  NPAG_BAP_MIN_PA

    (Alpha and Integrity servers) NPAG_BAP_MIN_PA specifies the
    lowest physical address in megabytes that is allowed in bus
    addressable pool (BAP).

185  –  NPAG_GENTLE

    Beginning with Version 8.2, the default values of NPAG_AGGRESSIVE
    and NPAG_GENTLE are 100. A value of 100 turns off both gentle
    and aggressive reclamation of nonpaged pool lookaside lists.
    In many cases, when pool reclamation moves small packets from
    the lookaside lists back to the variable list, the result is
    fragmentation of the variable list. This fragmentation appears
    as many small packets at the front of the variable list and a few
    large packets at the end of the list.

    When an allocation occurs for a packet that is larger than any
    of the lookaside lists, the system must find a large enough
    packet on the variable list. When heavily fragmented, the entire
    variable list often must be searched to find a large enough
    packet. Because the variable list is kept in address order, when
    a large packet is deallocated, the entire list must be searched
    again to deallocate the packet.

    Under these conditions, system performance can be severely
    degraded. For this reason, VSI recommends that you turn off pool
    reclamation but keep both NPAG_AGGRESSIVE and NPAG_GENTLE system
    parameters set to 100.

    NPAG_GENTLE is a DYNAMIC parameter.

186  –  NPAG_INTERVAL

    NPAG_INTERVAL is the number of seconds between passes of
    nonpaged-pool gentle reclamation.

    NPAG_INTERVAL is a DYNAMIC parameter.

187  –  NPAG_RING_SIZE

    NPAG_RING_SIZE represents the number of entries in the ring
    buffer.

188  –  PAGED_LAL_SIZE

    PAGED_LAL_SIZE sets the maximum size, in bytes, to use for the
    page dynamic pool lookaside lists. Use of these lookaside lists
    can reduce paged dynamic pool variable freelist fragmentation and
    improve paged pool allocation and deallocation performance.

    By default, PAGED_LAL_SIZE is set to 0, which disables the use of
    the paged dynamic pool lookaside lists.

    For environments experiencing paged pool variable freelist
    fragmentation a modest PAGED_LAL_SIZE, 512, has been adequate
    to improve paged pool performance and reduce fragmentation. If
    this parameter is made large and later decreased in size, some
    paged pool packets can be left unused until the parameter is made
    larger again, or the lookaside lists are reclaimed from due to a
    paged pool shortage. The paged dynamic pool lookaside lists will
    not occupy more than three-quarters of the available paged pool.

    PAGED_LAL_SIZE has DYNAMIC, GEN, and MAJOR attributes.

189  –  PAGFILCNT

    On Alpha and Integrity servers, beginning in OpenVMS Version 7.3,
    this parameter is obsolete.

    PAGFILCNT has the GEN attribute on VAX systems.

190  –  PAGTBLPFC

    PAGTBLPFC specifies (in pages) the maximum number of page tables
    to read to satisfy a fault for a nonresident page table.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

191  –  PAMAXPORT

    PAMAXPORT specifies the maximum port number to be polled on each
    CI and DSSI. The CI and DSSI port drivers poll to discover newly
    initialized ports or the absence/failure of previously responding
    remote ports.

    A system does not detect the existence of ports whose port
    numbers are higher than this parameter's value. Thus, set this
    parameter to a value that is equal to or greater than the highest
    port number being used on any CI or DSSI connected to the system.

    You can decrease this parameter to reduce polling activity if
    the hardware configuration has fewer than 16 ports. For example,
    if the CI or DSSI with the largest configuration has a total
    of 5 ports assigned to port numbers 0 through 4, you could set
    PAMAXPORT to 4.

    If CI or DSSI devices are not configured on your system, this
    parameter is ignored.

    The default for this parameter is 15 (poll for all possible ports
    0 through 15). VSI recommends that you set this parameter to the
    same value on each cluster computer.

    PAMAXPORT is a DYNAMIC parameter.

192  –  PANOPOLL

    Disables CI and DSSI polling for ports if set to 1. (The default
    is 0.) When PANOPOLL is set, a computer does not discover that
    another computer has shut down or powered down promptly and does
    not discover a new computer that has booted. This parameter is
    useful when you want to bring up a computer detached from the
    rest of the cluster for checkout purposes.

    PANOPOLL is functionally equivalent to uncabling the system from
    the DSSI or star coupler. This parameter does not affect OpenVMS
    Cluster communications by LAN.

    The default value of 0 is the normal setting and is required
    if you are booting from an HSC controller or if your system is
    joining an OpenVMS Cluster. This parameter is ignored if no CI or
    DSSI devices are configured on your system.

    PANOPOLL is a DYNAMIC parameter.

193  –  PANUMPOLL

    PANUMPOLL establishes the number of CI and DSSI ports to be
    polled each polling interval. The normal setting for PANUMPOLL
    is 16.

    On systems with less powerful CPUs, the parameter may be useful
    in applications sensitive to the amount of contiguous time that
    the system spends at IPL 8. Reducing PANUMPOLL reduces the amount
    of time spent at IPL 8 during each polling interval, while
    increasing the number of polling intervals needed to discover
    new or failed ports.

    If CI or DSSI devices are not configured on your system, this
    parameter is ignored.

    PANUMPOLL is a DYNAMIC parameter.

194  –  PAPOLLINTERVAL

    Specifies, in seconds, the polling interval the CI port driver
    uses to poll for a newly booted computer, a broken port-to-port
    virtual circuit, or a failed remote computer.

    This parameter trades polling overhead against quick response to
    virtual circuit failures. VSI recommends that you use the default
    value for this parameter.

    VSI recommends that you set this parameter to the same value on
    each cluster computer.

    PAPOLLINTERVAL is a DYNAMIC parameter.

195  –  PAPOOLINTERVAL

    Specifies, in seconds, the interval at which the port driver
    checks available nonpaged pool after a pool allocation failure.

    This parameter trades faster response to pool allocation failures
    against increased polling overhead. VSI recommends that you use
    the default value for this parameter.

    If CI or DSSI devices are not configured on your system, this
    parameter is ignored.

    PAPOOLLINTERVAL is a DYNAMIC parameter.

196  –  PASANITY

    PASANITY controls whether the CI and DSSI port sanity timers are
    enabled to permit remote systems to detect a system that has been
    hung at IPL 8 or above for 100 seconds. It also controls whether
    virtual circuit checking gets enabled on the local system. The
    TIMVCFAIL parameter controls the time (1-99 seconds).

    PASANITY is normally set to 1 and should be set to 0 only when
    you are debugging with XDELTA or planning to halt the CPU for
    periods of 100 seconds or more.

    PASANITY is only semidynamic. A new value of PASANITY takes
    effect on the next CI or DSSI port reinitialization.

    If CI or DSSI devices are not configured on your system, this
    parameter is ignored.

197  –  PASTDGBUF

    The number of datagram receive buffers to queue initially for the
    cluster port driver's configuration poller. The initial value is
    expanded during system operation, if needed.

    Memory Channel devices ignore this parameter.

    PASTDGBUF is an AUTOGEN parameter.

198  –  PASTIMOUT

    The basic interval at which the CI port driver wakes up to
    perform time-based bookkeeping operations. It is also the period
    after which a timeout is declared if no response to a start
    handshake datagram has been received.

    If CI or DSSI devices are not configured on your system, this
    parameter is ignored.

    The default value should always be adequate.

    PASTIMOUT is a DYNAMIC parameter.

199  –  PE1-6

    PE1, PE2, PE3, PE4, PE5, PE6 are reserved for VSI use only. These
    parameters are for cluster algorithms and their usages can change
    from release to release. VSI recommends using the default values
    for these special parameters.

200  –  PFCDEFAULT

    On Alpha and Integrity servers during execution of programs,
    PFCDEFAULT controls the number of image pagelets read from
    disk per I/O operation when a page fault occurs. The PFCDEFAULT
    maximum default value is 2032 512-byte pagelets (127 8192-byte
    Alpha and Integrity server pages).

    The read I/O operations can take place from an image file or
    from the page file. The actual size of the cluster can be less
    than PFCDEFAULT, depending on the size of image sections and the
    pattern of page references.

    The value should not be greater than one-fourth the default size
    of the average working set to prevent a single page fault from
    displacing a major portion of a working set. Too large a value
    for PFCDEFAULT can hurt system performance. PFCDEFAULT can be
    overridden on an image-by-image basis with the CLUSTER option of
    the OpenVMS linker.

    PFCDEFAULT has the AUTOGEN and DYNAMIC attributes.

201  –  PFN_COLOR_COUNT

    (Alpha and Integrity servers) PFN_COLOR_COUNT specifies the
    number of buckets (colors) into which all members of the zeroed
    page list and all unencumbered members of the free page list are
    sorted. OpenVMS Alpha systems might derive a preferred page color
    from a request to map a given virtual page and attempt to map
    that virtual page to a PFN of matching "color." This results in
    less variance in which cache blocks are used when accessing that
    page. This might or might not improve performance, depending on
    the application.

    This special parameter is use by VSI and is subject to change.
    Do not change this parameter unless VSI recommends that you do so.
    If you increase this parameter, you must also increase the ZERO_
    LIST_HI system parameter.

202  –  PFRATH

    PFRATH specifies the page fault rate above which the limit of
    a working set is automatically increased. The unit of measure
    is the number of faults per 10 seconds of processor time. At a
    setting of 120, for example, the system automatically increases
    the limit of a working set if it is faulting more than 120 pages
    per 10 seconds. Decreasing the value of this parameter tends to
    increase the limits of the working sets, while increasing its
    value tends to decrease their limits.

    On Alpha and Integrity servers, the default value is 8 page
    faults every 10 seconds.

    PFRATH has the DYNAMIC and MAJOR attributes. On Alpha and
    Integrity servers, PFRATH also is an AUTOGEN-altered parameter.

203  –  PFRATL

    PFRATL specifies the page fault rate below which the limit of
    a working set is automatically decreased. The unit of measure
    is the number of faults per 10 seconds of processor time. At a
    setting of 1, for example, the system automatically decreases the
    limit of a working set if it is faulting less than 1 page every
    10 seconds.

    Increasing the value of this parameter tends to decrease the
    limits of the working sets, while decreasing its value tends to
    increase their limits.

    PFRATL has the AUTOGEN, DYNAMIC, and MAJOR attributes.

204  –  PHYSICAL_MEMORY

    (Alpha and Integrity servers) PHYSICAL_MEMORY specifies the
    amount of physical memory available for use. The default setting
    is -1, which equates to all memory in the system. Decreasing this
    parameter allows you to test smaller configurations of memory
    without having to remove memory boards.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

    Because of hardware configuration requirements on the AlphaServer
    ES47/ES80/GS1280 systems, VSI does not recommend altering the
    setting of the system parameter PHYSICAL_MEMORY from its default
    setting of -1. Artificially reducing the amount of memory can
    produce unpredictable results on these systems.

    PHYSICAL_MEMORY is an AUTOGEN parameter.

    PHYSICALPAGES is an AUTOGEN parameter.

205  –  PIOPAGES

    PIOPAGES specifies the size of the process I/O segment, which
    holds data structures and buffer pool space for RMS to use
    when it handles I/O that involves process-permanent files. Once
    PIOPAGES is reset in SYSGEN, any new process receives the changed
    value.

    Beginning with OpenVMS Version 7.2, the default value has been
    raised to 575. The setting has been raised to accommodate the
    increased demands for process-permanent memory that result from
    changes made to RMS file-naming parsing in Version 7.2.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

    PIOPAGES is an AUTOGEN and DYNAMIC parameter.

206  –  PIXSCAN

    PIXSCAN specifies the number of process index slots scanned each
    second for computable or computable-outswapped processes. These
    processes receive an automatic priority boost for 1 quantum,
    unless the priority of the currently executing process is greater
    than 15. The priority boost is done to avoid potential deadlocks
    on the system.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

    PIXSCAN is an AUTOGEN and DYNAMIC parameter.

207  –  POOLCHECK

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

    POOLCHECK is used to investigate frequent and inexplicable
    failures in a system. When POOLCHECK is enabled, pool-checking
    routines execute whenever pool is deallocated or allocated.

    Two loadable forms of SYSTEM_PRIMITIVES.EXE are available at
    boot time. The default image, which contains no pool-checking
    code and no statistics maintenance, is loaded when POOLCHECK
    is set to zero. When POOLCHECK is set to a nonzero value, the
    monitoring version of SYSTEM_PRIMITIVES.EXE, which contains both
    pool-checking code and statistics maintenance, is loaded.

    Setting the SYSTEM_CHECK parameter to 1 has the effect of setting
    POOLCHECK to %X616400FF. For further information about pool
    checking, see the OpenVMS VAX Device Support Manual, (which is
    archived).

    POOLCHECK is a DYNAMIC parameter. However, for a change in its
    value to have any effect, POOLCHECK must be non-0 at boot time
    (to load the monitoring version of SYSTEM_PRIMITIVES.EXE).

208  –  POOLPAGING

    POOLPAGING enables (1)  paging of pageable dynamic pool.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

209  –  POWEROFF

    POWEROFF enables or disables software requests to the console
    firmware to remove power from the system. This parameter should
    normally be turned ON (1)  to allow software to make power-off
    requests. However, POWEROFF can be set to OFF (0)  to disable
    software power-off requests.

    If firmware or hardware support for the power-off request is not
    implemented, the shut-down procedure will leave the system halted
    but fully powered.

    POWEROFF is a DYNAMIC parameter.

210  –  PQL_DASTLM

    PQL_DASTLM sets the default limit on the number of pending ASTs
    for a process created by the Create Process ($CREPRC) system
    service or the DCL command RUN (Process).

    PQL_DASTLM has the DYNAMIC and GEN attributes.

211  –  PQL_DBIOLM

    PQL_DBIOLM sets the default buffered I/O count limit for the
    number of outstanding buffered I/O operations permitted to a
    process created by the Create Process ($CREPRC) system service or
    the DCL command RUN (Process).

    PQL_DBIOLM has the DYNAMIC and GEN attributes.

212  –  PQL_DBYTLM

    PQL_DBYTLM sets the default buffered I/O byte count limit for the
    amount of buffered space available to a process created by the
    Create Process ($CREPRC) system service or the DCL command RUN
    (Process).

    PQL_DBYTLM has the DYNAMIC and GEN attributes.

213  –  PQL_DCPULM

    PQL_DCPULM sets the default CPU time limit for a process created
    by the Create Process ($CREPRC) system service or the DCL command
    RUN (Process). PQL_DCPULM specifies the time limit in increments
    of 10 milliseconds.

    The default value of 0 imposes no limit on CPU time usage and is
    typically the correct value for this parameter.

    PQL_DCPULM has the DYNAMIC and GEN attributes.

214  –  PQL_DDIOLM

    PQL_DDIOLM sets the default direct I/O limit for a process
    created by the Create Process ($CREPRC) system service or the
    DCL command RUN (Process).

    PQL_DDIOLM has the DYNAMIC and GEN attributes.

215  –  PQL_DENQLM

    PQL_DENQLM sets the default enqueue limit for a process created
    by the Create Process ($CREPRC) system service or the DCL command
    RUN (Process).

    PQL_DENQLM has the DYNAMIC and GEN attributes.

216  –  PQL_DFILLM

    PQL_DFILLM sets the default open file limit for a process created
    by the Create Process ($CREPRC) system service or the DCL command
    RUN (Process).

    PQL_DFILLM has the DYNAMIC and GEN attributes.

217  –  PQL_DJTQUOTA

    PQL_DJTQUOTA sets the default job table byte count quota for a
    process created by the Create Process ($CREPRC) system service or
    the DCL command RUN (Process). PQL_DJTQUOTA specifies the number
    of bytes of paged pool allocated to the job table. The default
    value is usually adequate, unless a large number of job logical
    names or temporary mailboxes are used.

    PQL_DJTQUOTA is a DYNAMIC parameter.

218  –  PQL_DPGFLQUOTA

    PQL_DPGFLQUOTA sets the default page file quota for a process
    created by the Create Process ($CREPRC) system service or the DCL
    command RUN (Process). VSI recommends that this parameter not be
    smaller than the PQL_DWSEXTENT parameter.

    PQL_DPGFLQUOTA has the DYNAMIC and GEN attributes. On VAX
    systems, PQL_DPGFLQUOTA is also an AUTOGEN parameter.

219  –  PQL_DPRCLM

    PQL_DPRCLM sets the default subprocess limit for a process
    created by the Create Process ($CREPRC) system service or the
    DCL command RUN (Process).

    PQL_DPRCLM has the DYNAMIC and GEN attributes.

220  –  PQL_DTQELM

    PQL_DTQELM sets the default number of timer queue entries for a
    process created by the Create Process ($CREPRC) system service or
    the DCL command RUN (Process).

    PQL_DTQELM has the DYNAMIC and GEN attributes.

221  –  PQL_DWSDEFAULT

    PQL_DWSDEFAULT sets the default working set size for a process
    created by the Create Process ($CREPRC) system service or the DCL
    command RUN (Process).

    PQL_DWSDEFAULT has the AUTOGEN and GEN attributes.

222  –  PQL_DWSEXTENT

    PQL_DWSEXTENT sets the default working set extent for a process
    created by the Create Process ($CREPRC) system service or the DCL
    command RUN (Process).

    PQL_DWSEXTENT has the AUTOGEN, DYNAMIC, and GEN attributes.

223  –  PQL_DWSQUOTA

    PQL_DWSQUOTA sets the default working set quota for a process
    created by the Create Process ($CREPRC) system service or the DCL
    command RUN (Process).

    PQL_DWSQUOTA has the AUTOGEN, DYNAMIC, and GEN attributes.

224  –  PQL_MASTLM

    PQL_MASTLM sets a minimum limit on the number of pending ASTs for
    a process created by the Create Process ($CREPRC) system service
    or the DCL command RUN (Process).

    PQL_MASTLM has the DYNAMIC and GEN attributes.

225  –  PQL_MBIOLM

    PQL_MBIOLM sets the minimum buffered I/O limit for a process
    created by the Create Process ($CREPRC) system service or the DCL
    command RUN (Process).

    PQL_MBIOLM has the DYNAMIC and GEN attributes.

226  –  PQL_MBYTLM

    PQL_MBYTLM sets the minimum buffered I/O byte limit for a process
    created by the Create Process ($CREPRC) system service or the DCL
    command RUN (Process).

    PQL_MBYTLM has the DYNAMIC and GEN attributes.

227  –  PQL_MCPULM

    PQL_MCPULM sets the minimum CPU time limit in increments of
    10 milliseconds for a process created by the Create Process
    ($CREPRC) system service or the DCL command RUN (Process).

    PQL_MCPULM has the DYNAMIC and GEN attributes.

228  –  PQL_MDIOLM

    PQL_MDIOLM sets the minimum direct I/O limit for a process
    created by the Create Process ($CREPRC) system service or the
    DCL command RUN (Process).

    PQL_MDIOLM has the DYNAMIC and GEN attributes.

229  –  PQL_MENQLM

    PQL_MENQLM sets the minimum limit on the number of locks that can
    be queued at one time by a process created by the Create Process
    ($CREPRC) system service or the DCL command RUN (Process).

    PQL_MENQLM has the DYNAMIC and GEN attributes.

230  –  PQL_MFILLM

    PQL_MFILLM sets the minimum open file limit for a process created
    by the Create Process ($CREPRC) system service or the DCL command
    RUN (Process).

    PQL_MFILLM has the DYNAMIC and GEN attributes.

231  –  PQL_MJTQUOTA

    PQL_MJTQUOTA sets the minimum job table byte count quota for a
    process created by the Create Process ($CREPRC) system service or
    the DCL command RUN (Process).

    PQL_MJTQUOTA is a DYNAMIC parameter.

232  –  PQL_MPGFLQUOTA

    On VAX systems, PQL_MPGFLQUOTA sets the minimum page file quota
    for a process created by the Create Process ($CREPRC) system
    service or the DCL command RUN (Process). VSI recommends that this
    parameter be no smaller than PQL_MWSEXTENT.

    On Alpha and Integrity servers, PQL_MPGFLQUOTA sets the minimum
    pagelet file quota for a process created by the Create Process
    ($CREPRC) system service or the DCL command RUN (Process).

    PQL_MPQFLQUOTA has the DYNAMIC and GEN attributes. On VAX
    systems, PQL_MPQFLQUOTA is also an AUTOGEN parameter.

233  –  PQL_MPRCLM

    PQL_MPRCLM sets the minimum subprocess limit for a process
    created by the Create Process ($CREPRC) system service or the
    DCL command RUN (Process).

    PQL_MPRCLM has the DYNAMIC and GEN attributes.

234  –  PQL_MTQELM

    PQL_MTQELM sets the minimum number of timer queue entries for a
    process created by the Create Process ($CREPRC) system service or
    the DCL command RUN (Process).

    PQL_MTQELM has the DYNAMIC and GEN attributes.

235  –  PQL_MWSDEFAULT

    PQL_MWSDEFAULT sets the minimum default working set size for a
    process created by the Create Process ($CREPRC) system service or
    the DCL command RUN (Process).

    This value overrides a smaller quantity that is set for a user in
    AUTHORIZE.

    PQL_MWSDEFAULT has the AUTOGEN and GEN attributes.

236  –  PQL_MWSEXTENT

    PQL_MWSEXTENT sets the minimum working set extent for a process
    created by the Create Process ($CREPRC) system service or the DCL
    command RUN (Process).

    This value overrides a smaller quantity set for a user in
    AUTHORIZE.

    PQL_MWSEXTENT has the AUTOGEN, DYNAMIC, and GEN attributes.

237  –  PQL_MWSQUOTA

    PQL_MWSQUOTA sets the minimum working set quota for a process
    created by the Create Process ($CREPRC) system service or the DCL
    command RUN (Process).

    This value overrides a smaller quantity set for a user in
    AUTHORIZE.

    PQL_MWSQUOTA has the AUTOGEN, DYNAMIC, and GEN attributes.

238  –  PRCPOLINTERVAL

    PRCPOLINTERVAL specifies, in seconds, the polling interval used
    to look for Systems Communications Services (SCS) applications,
    such as the connection manager and mass storage control protocol
    disks, on other nodes. All discovered nodes are polled during
    each interval.

    This parameter trades polling overhead against quick recognition
    of new systems or servers as they appear.

    PRCPOLINTERVAL is a DYNAMIC parameter. On Alpha and Integrity
    servers, PRCPOLINTERVAL is also an AUTOGEN parameter.

239  –  PRIORITY_OFFSET

    PRIORITY_OFFSET specifies the difference in priority required
    by the scheduler for one process to preempt the current process.
    A value of 2, for example, means that if the current process
    is executing at priority 1, a computable process at priority 2
    or 3 is not allowed to preempt the current process. However, a
    priority 4 or higher process can preempt the current process.
    This mechanism affects only normal priority (0-15) processes. The
    default value is 0.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

240  –  PROCSECTCNT

    PROCSECTCNT sets the number of section descriptors that a process
    can contain. Each section descriptor increases the fixed portion
    of the process header by 32 bytes.

    Set a value greater than the maximum number of image sections
    in any section to be run, as indicated by the linkage memory
    allocation map for the image.

    PROCSECTCNT has the AUTOGEN and GEN attributes.

241  –  PU_OPTIONS

    PU_OPTIONS is reserved for VSI use only.

242  –  QDSKINTERVAL

    QDSKINTERVAL establishes, in seconds, the disk quorum polling
    interval. The default value is 3.

243  –  QDSKVOTES

    QDSKVOTES specifies the number of votes contributed by a quorum
    disk in a cluster.

244  –  QUANTUM

    QUANTUM defines the following:

    o  Processor time: maximum amount of processor time a process
       can receive before control passes to another process of equal
       priority that is ready to compute

    o  Balance set residency: minimum amount of service a compute-
       state process must receive before being swapped out to
       secondary storage

    QUANTUM has the DYNAMIC and MAJOR attributes. On Alpha and
    Integrity servers, QUANTUM also has the AUTOGEN attribute.

245  –  RAD_SUPPORT

    RAD_SUPPORT enables RAD-aware code to be executed
    on systems that support Resource Affinity Domains (RADs);
    for example, AlphaServer GS160 systems and Integrity
    cell-based servers or BL8x0c i2 servers. A RAD is a set of
    hardware components (CPUs and memory) with common access
    characteristics.

    Bits are defined in the RAD_SUPPORT parameter as follows:

    RAD_SUPPORT (default is 207 for Alpha and 10944667
    for Integrity servers)
    ___________________________________________________

     3   2 2   2 2         1 1
     1   8 7   4 3         6 5         8 7         0
    +-----+-----+-----------+-----------+-----------+
    |00|00| skip|ss|gg|ww|pp|00|00|00|00|0p|df|cr|ae|
    +-----+-----+-----------+-----------+-----------+

    Bit 0 (e): Enable    - Enables RAD support

    Bit 1 (a): Affinity  - Enables Soft RAD Affinity (SRA) scheduling
                           Also enables the interpretation of the skip
                           bits, 24-27.

    Bit 2 (r): Replicate - Enables system-space code replication

    Bit 3 (c): Copy      - Enables copy on soft fault

    Bit 4 (f): Fault     - Enables special page fault allocation
                           Also enables the interpretation of the
                           allocation bits, 16-23.

    Bit 5 (d): Debug     - Reserved to VSI

    Bit 6 (p): Pool      - Enables per-RAD non-paged pool

    Bits 7-15:           - Reserved to VSI

    Bits 16-23:          - If bit 4 is set, bits 16-23 are interpreted
                           as follows:

    Bits 16,17 (pp): Process = Pagefault on process (non global)
                               pages
    Bits 18,19 (ww): Swapper = Swapper's allocation of pages for
                               processes
    Bits 20,21 (gg): Global  = Pagefault on global pages
    Bits 22,23 (ss): System  = Pagefault on system space pages

    Encodings for pp, ww, gg, ss:
    Current  (0) - allocate PFNs from the current CPU's RAD
    Random   (1) - allocate PFNs using the "random" algorithm
    Base     (2) - allocate PFNs from the operating system's "base"
                   RAD
    Home     (3) - allocate PFNs from the current process's home RAD

    If bits 16-23 are 0, the defaults for pp, ww, gg, ss are interpreted
    as follows:

        Process = home RAD
        Swapper = current RAD (also sets home RAD for process)
        Global  = random RAD
        System  = base RAD

    Bits 24-27:   - If bit 1 is set, bits 24-27 are interpreted
                    as a skip count value (power of 2). Example: If
                    bits 24-27 contain a 3, the skip count is 8.
                    If bits 24-27 contain a 5, the skip count is 32.
                    If bits 24-27 are 0, the default of 16 is used
                    as the skip count.

    Bits 28-31:   - Reserved to VSI

    For more information about using OpenVMS RAD features, see the
    OpenVMS Alpha Galaxy and Partitioning Guide or VSI OpenVMS
    Version 8.4 New Features and Documentation Overview.

    RAD_SUPPORT has the GEN attribute.

    REALTIME_SPTS has the DYNAMIC, GEN, and MAJOR attributes.

246  –  RECNXINTERVAL

    RECNXINTERVAL establishes the polling interval, in seconds,
    during which to attempt reconnection to a remote system.

    RECNXINTERVAL is a DYNAMIC parameter. On Alpha and Integrity
    servers, RECNXINTERVAL is also an AUTOGEN parameter.

247  –  RESALLOC

    RESALLOC controls whether resource allocation checking is
    performed. The default value of 0 disables resource allocation
    checking.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

248  –  RESHASHTBL

    RESHASHTBL defines the number of entries in the lock management
    resource name hash table. Each entry requires 4 bytes. A typical
    tuning goal is to have the RESHASHTBL parameter about four times
    larger than the total number of resources in use on the system.
    Managers of systems with memory constraints or systems that are
    not critically dependent on locking speed could set the table to
    a smaller size.

    RESHASHTBL has the AUTOGEN, FEEDBACK, and MAJOR attributes.

249  –  RJOBLIM

    RJOBLIM defines the maximum number of remote terminals allowed in
    the system at any one time.

    RJOBLIM is a DYNAMIC parameter.

250  –  RMS_CONPOLICY

    RMS_CONPOLICY specifies the policy to be used for dealing with
    high-contention write-shared files. This dynamic parameter can
    be used to ensure fairness between lock conversions and new lock
    requests.

    Possible values are the following:

    Value          Explanation

    NEVER          (Default) Never use the higher overhead option
                   to improve fairness for any write-shared files
                   accessed on the system; minimal overhead.
    SOMETIMES      Use this option for fairer bucket access (but
                   higher overhead) to any write-shared files with
                   global buffers enabled that are accessed on the
                   system.
    ALWAYS         Use this option for fairer bucket access (but
                   higher overhead) to all write-shared files
                   accessed on the system.

    You can set this system parameter with the DCL command SET RMS_
    DEFAULT/SYSTEM/CONTENTION_POLICY=value and display the parameter
    with the DCL command SHOW RMS_DEFAULT.

    RMS_CONPOLICY is a DYNAMIC parameter.

251  –  RMSD*

    RMSD1, RMSD2, RMSD3, RMSD4, RMSD5, RMSD6, and RMSD7 are special
    parameters reserved for VSI use.

    RMSD* parameters are DYNAMIC.

252  –  RMS_DFLRL

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

    RMS_DFLRL is a DYNAMIC parameter.

253  –  RMS_DFMBC

    RMS_DFMBC specifies a default multiblock count only for record
    I/O operations, where count is the number of blocks to be
    allocated for each I/O buffer.

    You can set this system parameter with the DCL command SET RMS_
    DEFAULT/SYSTEM and display the parameter with the SHOW RMS_
    DEFAULT command.

    RMS_DFMBC is an AUTOGEN and DYNAMIC parameter.

254  –  RMS_DFMBFIDX

    RMS_DFMBFIDX establishes the default RMS multibuffer count for
    indexed sequential disk operations. This value defines the number
    of I/O buffers that RMS allocates for each indexed file. For
    sequential access, a larger number that allows some of the index
    buckets to remain in memory can improve performance.

    You can set this system parameter with the DCL command
    SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_
    DEFAULT.

    RMS_DFMBFIDX is an AUTOGEN and DYNAMIC parameter.

255  –  RMS_DFMBFREL

    RMS_DFMBFREL establishes the default RMS multibuffer count for
    relative disk operations. This value defines the number of I/O
    buffers that RMS allocates for each relative file.

    You can set this system parameter with the DCL command
    SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_
    DEFAULT.

    RMS_DFMBFREL is an AUTOGEN and DYNAMIC parameter.

256  –  RMS_DFMBFSDK

    RMS_DFMBFSDK establishes the default RMS multibuffer count for
    sequential disk operations. This value defines the number of I/O
    buffers that RMS allocates for sequential disk files.

    The default value is usually adequate. However, if read-ahead
    or write-behind operations are used, a larger number improves
    performance.

    You can set this system parameter with the DCL command
    SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_
    DEFAULT.

    RMS_DFMBFSDK is an AUTOGEN and DYNAMIC parameter.

257  –  RMS_DFMBFSMT

    RMS_DFMBFSMT establishes the default RMS multibuffer count for
    magnetic tape operations. This value defines the number of I/O
    buffers that RMS allocates for magnetic tape files.

    You can set this system parameter with the DCL command
    SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_
    DEFAULT.

    RMS_DFMBFSMT is an AUTOGEN and DYNAMIC parameter.

258  –  RMS_DFMBFSUR

    RMS_DFMBFSUR establishes the default multibuffer count for unit
    record devices.

    You can set this system parameter with the DCL command
    SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_
    DEFAULT.

    RMS_DFMBFSUR is an AUTOGEN and DYNAMIC parameter.

259  –  RMS_DFNBC

    RMS_DFNBC specifies a default block count for network access to
    remote, sequential, indexed sequential, and relative files.

    The network block count value represents the number of blocks
    that RMS is prepared to allocate for the I/O buffers used to
    transmit and receive data. The buffer size used for remote file
    access, however, is the result of a negotiation between RMS and
    the remote file access listener (FAL). The buffer size chosen is
    the smaller of the two sizes presented.

    Thus, RMS_DFNBC places an upper limit on the network buffer size
    that is used. It also places an upper limit on the largest record
    that can be transferred to or from a remote file. In other words,
    the largest record that can be transferred must be less than or
    equal to RMS_DFNBC multiplied by 512 bytes.

    You can set this system parameter with the DCL command
    SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_
    DEFAULT.

    RMS_DFNBC is an AUTOGEN and DYNAMIC parameter.

260  –  RMS_EXTEND_SIZE

    RMS_EXTEND_SIZE specifies the number of blocks by which files
    are extended as they are written. This number should be chosen to
    balance the amount of extra disk space wasted at the ends of each
    file against the performance improvement provided by making large
    extents infrequently.

    When small disk quotas are used, specify a small number such as
    the disk cluster size to prevent the user's disk quota from being
    consumed. If the value of 0 is used, RMS allocates large extents
    and truncates the file back to its actual usage when it closes.

    You can set this system parameter with the DCL command
    SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_
    DEFAULT.

    RMS_EXTEND_SIZE is a DYNAMIC parameter.

261  –  RMS_FILEPROT

    RMS_FILEPROT determines the default file protection for system
    processes such as those that create the error log, operator log,
    and job controller. It also determines default file protection
    for processes created by the job controller (all interactive and
    batch processes).

    Because a process always inherits its default file protection
    from its creator process, RMS_FILEPROT determines default file
    protection only for users who do not execute the DCL command SET
    PROTECTION/DEFAULT in their login command procedures or during
    interactive sessions.

    The protection is expressed as a mask. (See the discussion of
    the $CRMPSC system service in the VSI OpenVMS System Services
    Reference Manual for more information about specifying protection
    masks.) By default, the mask is 64000 (decimal) or FA00
    (hexadecimal), which represents the following protection:

    (S:RWED,O:RWED,G:RE,W:)

262  –  RMS_HEURISTIC

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

    RMS_HEURISTIC is a DYNAMIC parameter.

263  –  RMS_PATH_TMO

    The RMS path cache in each process holds entries that translate
    DVI+DID+name to new DVI+DID. These are used to greatly speed
    up directory path walks. Cache entries representing ordinary
    directory lookups are invalidated through the volume directory
    sequence number mechanism (UDB$L_DIRSEQ), which is clocked
    on every volume dismount and each time a directory is deleted
    or renamed. However, there is no convenient mechanism for
    invalidating a cache entry that represents a symlink, whose
    interpretation is affected by logical names or modification of
    the symlink. The only way to eliminate stale cache entries is
    with a timeout. This parameter is the system-wide cache timeout.
    Special values:

          1 = don't keep cache entries
         -1 = keep cache entries forever
 RMS_PATH_TMO is a DYNAMIC parameter.

264  –  RMS_PROLOGUE

    RMS_PROLOGUE specifies the default prologue RMS uses to create
    indexed files. The default value 0 specifies that RMS should
    determine the prologue based on characteristics of the file. A
    value of 2 specifies Prologue 2 or Prologue 1, and 3 specifies
    Prologue 3. The RMS prologues are described in the OpenVMS Record
    Management Services Reference Manual.

    RMS_PROLOGUE is a DYNAMIC parameter.

265  –  RMS_SEQFILE_WBH

    (Alpha and Integrity servers) RMS_SEQFILE_WBH can enable the
    RMS writebehind feature as a system default for any unshared
    sequential disk file if the file is opened for image I/O with
    write access specified. The possible settings are the following:

    Setting        Description

    0 (default)    Do not enable writebehind feature. Preserve prior
                   behavior of using writebehind only if the user
                   requests it by setting RAB$V_WBH in RAB$L_ROP.

    1              Enable writebehind feature as system default,
                   including the allocation of at least two local
                   buffers.

    RMS_SEQFILE_WBH is a DYNAMIC parameter.

266  –  S0_PAGING

    S0_PAGING controls paging of system code:

    o  Setting bit 0 disables paging of all Exec code and data.

    o  Setting bit 1 disables paging of all RMS code and data.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

267  –  S2_SIZE

    (Alpha and Integrity servers) S2_SIZE is the number of megabytes
    to reserve for S2 space. This value does not include the size
    required for extended file cache (XFC).

268  –  SAVEDUMP

    If the dump file is saved in the page file, SAVEDUMP specifies
    whether the page file is saved until the dump file is analyzed.
    The default value 0 specifies that the page file should not be
    retained. A value of 1 specifies that the dump written to the
    page file should be retained until either copied or released
    using the SDA utility.

269  –  SCHED_FLAGS

    Special DYNAMIC parameter reserved for VSI use.

270  –  SCH_HARD_OFFLD

    The scheduler hard off-load parameter is a CPU bitmask parameter.
    The bits correspond to CPU IDs. For any bit set, the OpenVMS
    scheduler does not schedule processes on this CPU unless the
    process has hard affinity set for the CPU. In addition, a process
    with the PRIMARY capability requirement will ignore the bit
    corresponding to the primary CPU.

    SCH_HARD_OFFLD is a DYNAMIC parameter.

271  –  SCH_SOFT_OFFLD

    The scheduler soft off-load parameter is a CPU bitmask parameter.
    The bits correspond to CPU IDs. For any bit set, the OpenVMS
    scheduler tries to avoid scheduling processes on this CPU.
    However, if no other idle CPUs exist, processes are still
    scheduled on this CPU.

    SCH_SOFT_OFFLD is a DYNAMIC parameter.

272  –  SCSBUFFCNT

    On VAX systems, SCSBUFFCNT is the number of buffer descriptors
    configured for all systems communication architecture (SCA). If
    an SCA device is not configured on your system, this parameter is
    ignored. Generally speaking, each data transfer needs a buffer
    descriptor and thus the number of buffer descriptors can be
    a limit on the number of possible simultaneous I/Os. Various
    performance monitors report when a system is out of buffer
    descriptors for a given workload which is an indication that
    a larger value for SCSBUFFCNT is worth considering. Note that
    AUTOGEN provides feedback for this parameter on VAX systems only.

    On Alpha and Integrity servers, the system communication services
    (SCS) buffers are allocated as needed, and SCSBUFFCNT is reserved
    for VSI use only.

    SCSBUFFCNT has the AUTOGEN, FEEDBACK, and GEN attributes.

273  –  SCSFLOWCUSH

    Specifies the lower limit for receive buffers at which point
    system communication services (SCS) starts to notify the remote
    SCS of new receive buffers. For each connection, SCS tracks the
    number of receive buffers available. SCS communicates this number
    to the SCS at the remote end of the connection. However, SCS does
    not need to do this for each new receive buffer added. Instead,
    SCS notifies the remote SCS of new receive buffers if the number
    of receive buffers falls as low as the SCSFLOWCUSH value.

    The default value is adequate on most systems. If a systems
    communication architecture (SCA) port is not configured on your
    system, this parameter is ignored.

    SCSFLOWCUSH is a DYNAMIC parameter.

274  –  SCSI_ERROR_POLL

    If an error occurs while a particular initiator is accessing
    a SCSI device, that error is latched for all other initiators
    and is not unlatched and reported to the other initiators until
    the next time they access the device. Therefore, if the other
    initiators do not access the device in a timely manner, the
    reporting of the error can be greatly delayed, which can cause
    confusion.

    The purpose of SCSI_ERROR_POLL is to cause OpenVMS to send a
    SCSI Test Unit Ready command every hour to each SCSI disk, in
    an attempt to force latched errors to become unlatched and to
    be reported immediately. SCSI_ERROR_POLL has a default value of
    1. It can, however, be set to 0 by the user in order to stop the
    error polling activity.

    The parameter affects SCSI disks connected by Fibre Channel as
    well as parallel SCSI. If the disk has multiple paths, then the
    error polling is performed on all non-served paths to the disk.
    Tapes and other non-disk devices are not subject to this error
    polling, regardless of the parameter setting.

    SCSI_ERROR_POLL is a DYNAMIC parameter.

    SCSI_NOAUTO is a DYNAMIC parameter.

275  –  SCSICLUSTER_P[1-4]

    (Alpha only) SCSICLUSTER_P[1-4] parameters allow non-HP
    peripherals (CPU-lookalikes) in SCSI clusters.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

276  –  SCSMAXDG

    This parameter is reserved for VSI use only.

    SCSMAXDG has the GEN attribute.

277  –  SCSMAXMSG

    This parameter is reserved for VSI use only.

    SCSMAXMSG has the GEN attribute.

278  –  SCSNODE

    SCSNODE specifies the name of the computer. This parameter is not
    dynamic.

    Specify SCSNODE as a string of up to six characters. Enclose the
    string in quotation marks.

                                   NOTE

       The maximum size of six characters is strictly enforced.
       SYSBOOT truncates the value of SCSNODE if the size of the
       system parameter is set to more than six characters.

    If the computer is in an OpenVMS Cluster, specify a value that is
    unique within the cluster. Do not specify the null string.

    If the computer is running DECnet for OpenVMS, the value must be
    the same as the DECnet node name.

    SCSNODE has the AUTOGEN and GEN attributes.

279  –  SCSRESPCNT

    SCSRESPCNT is the total number of response descriptor table
    entries (RDTEs) configured for use by all system applications.

    If SCA or DSA ports are not configured on your system, the system
    ignores SCSRESPCNT.

    SCSRESPCNT has the AUTOGEN, FEEDBACK, and GEN attributes.

280  –  SCSSYSTEMID

    Specifies a number that identifies the computer. This parameter
    is not dynamic. SCSSYSTEMID is the low-order 32 bits of the 48-
    bit system identification number.

    If the computer is in an OpenVMS Cluster, specify a value that is
    unique within the cluster. Do not use zero as the value.

    If the computer is running DECnet for OpenVMS, calculate the
    value from the DECnet address using the following formula:

    SCSSYSTEMID = ((DECnet area number) * 1024) + (DECnet node number)

    Example: If the DECnet address is 2.211, calculate the value as
    follows:

    SCSSYSTEMID = (2 * 1024) + 211 = 2259

    SCSSYSTEMID has the GEN attribute.

281  –  SCSSYSTEMIDH

    Specifies the high-order 16 bits of the 48-bit system
    identification number. This parameter must be set to 0. It is
    reserved by VSI for future use.

    SCSSYSTEMIDH has the GEN attribute.

282  –  SECURITY_POLICY

    SECURITY_POLICY allows a system to run in a C2 or B1
    configuration and to subset out particular pieces of
    functionality-to exclude functionality that is outside the
    evaluated configuration or to preserve compatibility with
    previous versions of the operating system. See the VSI OpenVMS
    Guide to System Security for further information about the C2 and
    B1 evaluated configurations.

    The following bits are defined:

    Bit   Description

    0     Obsolete.

    1     Allows multiple user names to connect to DECW$SERVER.

    2     Allows unevaluated DECwindows transports (such as TCP/IP).

    3     Allows $SIGPRC and $PRCTERM to span job trees.

    4     Allows security profile changes to protected objects on
          a local node when the object server is absent and cannot
          update the cluster database VMS$OBJECTS.DAT.

    5     Allows creation of protected objects on a local node when
          the object server is absent and cannot update the cluster
          database VMS$OBJECTS.DAT.

    6     Allows SPAWN or LIB$SPAWN commands in CAPTIVE accounts.

    7     Reserved to VSI.

    8     Reserved to VSI.

    9     Disables password synchronizations among ACME agents on
          a systemwide pasis. This is functionally equivalent to
          the SYS$SINGLE_SIGNON logical name bit mask value 4 for
          LOGINOUT.

    10    Allows privileged applications to successfully authenticate
          a user whose principal name maps to a SYSUAF record that is
          either expired or whose modal restrictions would otherwise
          prevent the account from being used.

          A SYSUAF record that is disabled or password-expired (in
          the case of traditional OpenVMS authentication) cannot be
          bypassed in this manner.

          An application with SECURITY privilege specifies the
          SYS$ACM ACME$M_NOAUTHORIZE function modifier to override
          authorization checks.

    11    Allows any record in the SYSUAF file to be mapped using
          external authentication.

    12    Allows intrusions on a clusterwide or local basis. (If the
          bit is cleared, intrusions are clusterwide.)

    13    Reserved to VSI.

    14    Allows the internal name and backlink of files and
          directories to be read if the user has either execute or
          read access to the file or directory. If this bit is clear,
          read access is required.

          Setting this bit allows the full POSIX pathname of a file
          or directory to be displayed when some of the directories
          in the path are execute-only to the user. This feature is
          required in the following environments:

          o  POSIX pathnames are in use.

          o  The BASH shell or other GNV components are in use.

          o  Applications are using the realpath(),  getcwd(),
             getpwnam(),  and related C runtime library functions.

    The default value of 7 preserves compatibility with existing
    DECwindows Motif behavior. A value of 0 disables all unevaluated
    configurations.

283  –  SETTIME

    SETTIME enables (1)  or disables (0) solicitation of the time of
    day each time the system is booted. This parameter should usually
    be off (0), so that the system sets the time of day at boot time
    to the value of the processor time-of-day register. You can reset
    the time after the system is up with the DCL command SET TIME
    (see the VSI OpenVMS DCL Dictionary).

284  –  SHADOW_D1-D5

    Special DYNAMIC parameters reserved for VSI use.

285  –  SHADOW_ENABLE

    Special parameter reserved for VSI use.

286  –  SHADOWING

    SHADOWING loads the host-based volume shadowing driver. See VSI
    Volume Shadowing for OpenVMS for more information about setting
    system parameters for volume shadowing.

    Specify one of the following values:

    Value  Description

    0      No shadowing is enabled; SHDRIVER is not loaded. This is
           the default value.

    2      Host-based volume shadowing enabled; SHDRIVER is loaded.
           Host-based volume shadowing provides shadowing of all
           disks located on a standalone system or an OpenVMS Cluster
           system.

287  –  SHADOW_HBMM_RTC

    (Alpha and Integrity servers) SHADOW_HBMM_RTC specifies, in
    seconds, how frequently each shadow set on this system has its
    modified block count compared with the reset threshold. If the
    modified block count exceeds the reset threshold, the bitmap for
    that shadow set is zeroed. This comparison is performed for all
    shadow sets mounted on the system that have HBMM bitmaps.

    The reset threshold is specified by the RESET_THRESHOLD keyword
    in the /POLICY qualifier of the SET SHADOW command.

    When the comparison is made, the modified block count might
    exceed the reset threshold by a small increment or by a much
    larger amount. The difference depends on the write activity to
    the volume and on the setting of this parameter.

    SHADOW_HBMM_RTC is a DYNAMIC parameter.

288  –  SHADOW_MAX_COPY

    The value of SHADOW_MAX_COPY controls how many parallel copy
    threads are allowed on a given node.

    Carefully consider the needs of each shadowed node when you
    set this parameter. Too high a value for SHADOW_MAX_COPY can
    affect performance by allowing too many copy threads to operate
    in parallel. Too low a value unnecessarily restricts the number
    of threads your system can effectively handle.

    See VSI Volume Shadowing for OpenVMS for more information about
    setting system parameters for volume shadowing.

    SHADOW_MAX_COPY has the AUTOGEN and DYNAMIC attributes.

289  –  SHADOW_MAX_UNIT

    SHADOW_MAX_UNIT specifies the maximum number of shadow sets that
    can exist on a system. The setting must be equal to or greater
    than the number of shadow sets you plan to have on a system.
    Dismounted shadow sets, unused shadow sets, and shadow sets with
    no write bitmaps allocated to them are included in the total.

                                   NOTE

       Review this default carefully. The setting must be equal to
       or greater than the number of shadow sets you plan to have
       on a system. If you attempt to mount more shadow sets than
       the number specified by SHADOW_MAX_UNIT, the MOUNT command
       will fail. Dismounted shadow sets, unused shadow sets, and
       shadow sets with no write bitmaps allocated to them are
       included in the count for SHADOW_MAX_UNIT.

    On Alpha and Integrity servers, the default value for this system
    parameter is 500, which consumes 24 KB of main memory.

    If you do not plan to use Volume Shadowing for OpenVMS, you can
    change the setting to its minimum of 10 (which consumes 480 bytes
    of main memory). Setting the default to its minimum frees up 23.5
    KB of main memory on an OpenVMS Alpha or Integrity servers and
    4.5 KB of main memory on a VAX system. (The maximum value of this
    parameter is 10,000.)

    This system parameter is not dynamic; that is, a reboot is
    required when you change the setting.

290  –  SHADOW_MBR_TMO

    SHADOW_MBR_TMO controls the amount of time the system tries to
    fail over physical members of a shadow set before removing them
    from the set. The SHADOW_MBR_TMO parameter replaces the temporary
    VMSD3 parameter used in prior releases.

    The SHADOW_MBR_TMO parameter is valid for use only with Phase II
    of Volume Shadowing for OpenVMS. You cannot set this parameter
    for use with Phase I, which is obsolete.

    Use the SHADOW_MBR_TMO parameter (a word) to specify the number
    of seconds, in decimal from 1 to 65,535, during which recovery
    of a repairable shadow set is attempted. If you do not specify
    a value or if you specify 0, the default delay of 120 seconds is
    used.

    Because SHADOW_MBR_TMO is a dynamic parameter, you should use the
    SYSGEN command WRITE CURRENT to permanently change its value.

    SHADOW_MBR_TMO is a DYNAMIC parameter.

291  –  SHADOW_PSM_RDLY

    When a copy or merge operation is needed on a shadow set that is
    mounted on more than one system, the shadowing driver attempts
    to perform the operation on a system that has a local connection
    to all the shadow set members. Shadowing implements the copy or
    merge operation by adding a time delay based on the number of
    shadow set members that are MSCP-served to the system. No delay
    is added for local members; a system with all locally accessible
    shadow set members usually performs the copy or merge before a
    system on which one or more members is served (and therefore is
    delayed) does.

    SHADOW_PSM_RDLY allows the system manager to adjust the delay
    that shadowing adds. By default, the delay is 30 seconds for each
    MSCP-served shadow set member. The valid range for the specified
    delay is 0 through 65,535 seconds.

    When a shadow set is mounted on a system, the value of SHADOW_
    PSM_RDLY is used as the default shadow set member recovery delay
    for that shadow set. To modify SHADOW_PSM_RDLY for an existing
    shadow set, see the SET SHADOW/ /RECOVERY_OPTIONS=DELAY_PER_
    SERVED_MEMBER=n command in VSI Volume Shadowing for OpenVMS.

292  –  SHADOW_REC_DLY

    (Alpha and Integrity servers)

    The value of the SHADOW_REC_DLY parameter specifies the length
    of time a system waits before it attempts to manage recovery
    operations on shadow sets that are mounted on the system.
    A shadow set is said to need recovery when a merge or copy
    operation is required on that shadow set.

    SHADOW_REC_DLY can be used to better predict which systems in
    an OpenVMS Cluster performs recovery operations. This is done
    by setting lower values of SHADOW_REC_DLY on systems that are
    preferred to handle recovery operations and higher values of
    SHADOW_REC_DLY on systems that are least preferred to handle
    recovery operations.

    The range of SHADOW_REC_DLY is 20 to 65535 seconds. The default
    value is 20 seconds.

    For more information about controlling which systems perform the
    merge or copy operations, see VSI Volume Shadowing for OpenVMS.

    SHADOW_REC_DLY is a DYNAMIC parameter.

293  –  SHADOW_SITE_ID

    (Alpha and Integrity servers) This parameter allows a system
    manager to define a site value, which Volume Shadowing uses to
    determine the best device to perform reads, thereby improving
    performance.

    The system manager can now define the site value to be used
    for all shadow sets mounted on a system. This parameter is an
    arbitrary numeric value coordinated by the system manager of
    disaster tolerant clusters. Reads from devices that have site
    values matching the shadow set's site value are preferred over
    reads from devices with different site values. For detailed
    information, see the description of the $SET DEVICE/SITE in the
    VSI OpenVMS DCL Dictionary and VSI Volume Shadowing for OpenVMS.

    SHADOW_SITE_ID is a DYNAMIC parameter.

294  –  SHADOW_SYS_DISK

    A SHADOW_SYS_DISK parameter value of 1 enables shadowing of the
    system disk. A value of 0 disables shadowing of the system disk.
    The default value is 0.

    Also specify a system disk shadow set virtual unit number with
    the SHADOW_SYS_UNIT system parameter, unless the desired system
    disk unit number is DSA0.

    A value of 4096 enables CI-based minimerge. To enable minimerge
    on a system disk, however, you must enable DOSD by setting the
    DUMPSTYLE parameter to dump off system disk, as described in the
    VSI OpenVMS System Manager's Manual. You can then add the value
    4096 to your existing SHADOW_SYS_DISK value. For example, if you
    have SHADOW_SYS_DISK set to a value of 1, change it to 4097 to
    enable minimerge.

295  –  SHADOW_SYS_TMO

    The SHADOW_SYS_TMO parameter has the following two distinct uses:

    o  At system boot time, when this is the first node in the
       cluster to boot and to create this specific shadow set. If the
       proposed shadow set is not currently mounted in the cluster,
       use this parameter to extend the time a booting system waits
       for all former members of the shadowed system disk to become
       available.

    o  Once the system successfully mounts the virtual unit and
       begins normal operations. In this usage, the SHADOW_SYS_
       TMO parameter controls the time the operating system waits
       for errant members of a system disk. (Use the SHADOW_MBR_TMO
       parameter to control the time the operating system waits for
       the errant members of an application disk.)

    This parameter applies only to members of the system disk shadow
    set. All nodes using a particular system disk shadow set should
    have their SHADOW_SYS_TMO parameter set to the same value once
    normal operations begin.

    The default value is 120 seconds. Change this parameter to a
    higher value if you want the system to wait more than the 120-
    second default for all members to join the shadow set. You can
    set the parameter value to 120 through 65,535 seconds.

296  –  SHADOW_SYS_UNIT

    Use this parameter for Phase II shadowing only. The SHADOW_SYS_
    UNIT parameter is an integer value that contains the virtual unit
    number of the system disk. The default value is 0. The maximum
    value allowed is 9999. This parameter is effective only when the
    SHADOW_SYS_DISK parameter has a value of 1. This parameter should
    be set to the same value on all nodes booting off a particular
    system disk shadow set. See VSI Volume Shadowing for OpenVMS
    for more information about setting system parameters for volume
    shadowing.

297  –  SHADOW_SYS_WAIT

    The SHADOW_SYS_WAIT parameter extends the time a booting system
    waits for all current members of a mounted shadowed system disk
    to become available to this node. The shadow set must already be
    mounted by at least one other cluster node for this parameter to
    take effect.

    The default value is 480 seconds. Change this parameter to a
    higher value if you want the system to wait more than the 480-
    second default for all members to join the shadow set. You can
    set the parameter value to 1 through 65,535 seconds.

298  –  SMCI_FLAGS

    (Alpha Galaxy platforms only) The SMCI_FLAGS parameter controls
    operational aspects of SYS$PBDRIVER, the Galaxy Shared Memory
    Cluster Interconnect (SMCI).

    Bits in the bit mask are the following:

    Bit  Mask                        Description

    0    0     0 =  Do not create local communications channels
                    (SYSGEN default). Local SCS communications are
                    primarily used in test situations and are not
                    needed for normal operations. Not creating local
                    communications saves resources and overhead.

               1 =  Create local communications channels.

    1    2     0 =  Load SYS$PBDRIVER if booting into both a Galaxy
                    and a Cluster (SYSGEN Default).

               1 =  Load SYS$PBDRIVER if booting into a Galaxy.

    2    4     0 =  Minimal console output (SYSGEN default).

               1 =  Full console output; SYS$PBDRIVER displays
                    console messages when it creates and tears down
                    communications channels.

    SMCI_FLAGS has the DYNAMIC attribute.

299  –  SMCI_PORTS

    On systems running OpenVMS Galaxy software, the Shared Memory
    Cluster Interconnect (SMCI) system parameter SMCI_PORTS controls
    initial loading of SYS$PBDRIVER. This parameter is a bit mask;
    bits 0 through 25 each represent a controller letter. If bit 0
    is set, which is the default setting, PBAx is loaded (where x
    represents the Galaxy Partition ID). If bit 1 is set, PBBx is
    loaded, and so on up to bit 25, which causes PBZx to be loaded.
    For OpenVMS Alpha Version 7.2 and later, VSI recommends leaving
    this parameter at the default value of 1.

    Loading additional ports allows multiple paths between Galaxy
    instances. In the initial release of the Galaxy software, having
    multiple communications channels is not an advantage because
    SYS$PBDRIVER does not support fast path. A future release
    of OpenVMS will provide Fast Path support for SYS$PBDRIVER,
    when multiple CPUs improve throughput by providing multiple
    communications channels between instances.

300  –  SMP_CPU_BITMAP

    This parameter indicates that the corresponding CPU is a bitmap
    representing up to 1024 CPUs. Each bit set in this bitmap
    indicates that the corresponding CPU automatically attempts
    to join the active set in an OpenVMS symmetric multiprocessing
    environment when the instance is booted. A cleared bit indicates
    that the corresponding CPU is ignored only at boot time; if it is
    otherwise viable, the CPU can be started at a later time.

    SMP_CPU_BITMAP defaults to all bits set. (CPU 0 through CPU 1023
    are enabled for multiprocessing.) Note that the primary processor
    is always booted regardless of the setting of the corresponding
    bit in the CPU bitmap.

    To change the value of SMP_CPU_BITMAP in SYSBOOT or SYSGEN,
    specify a list of individual bits or contiguous groups of bits.
    For example:

       SYSGEN> SET SMP_CPU_BITMAP 0,5,17-21

    The command in this example sets bits 0, 5, 17, 18, 19, 20, and
    21 in the bitmap and clears all other bits.

    This parameter replaces the SMP_CPUS parameter.

301  –  SMP_LNGSPINWAIT

    SMP_LNGSPINWAIT establishes, in 10-microsecond intervals, the
    amount of time a CPU in an SMP system normally waits for access
    to a shared resource. This process is called spinwaiting.

    Generally spinlocks at IPL <= 8 have long holding times,
    therefore have their timeout intervals set to SMP_LNGSPINWAIT
    to prevent SPINWAIT timeouts in cases of nested acquisition.

    A timeout causes a CPUSPINWAIT bugcheck.

    The default value is 3000000 (30,00, 000 10-microsecond intervals
    or 30 second).

302  –  SMP_SANITY_CNT

    SMP_SANITY_CNT establishes, in 10-millisecond intervals, the
    timeout period for each CPU in a symmetric multiprocessing (SMP)
    system. Each CPU in an SMP system monitors the sanity timer of
    one other CPU in the configuration to detect hardware or software
    failures. If allowed to go undetected, these failures could cause
    the cluster to hang. A timeout causes a CPUSANITY bugcheck.

    The default value is 300 milliseconds (30 10-millisecond
    intervals).

303  –  SMP_SPINWAIT

    SMP_SPINWAIT establishes, in 10-microsecond intervals, the amount
    of time a CPU in an SMP system normally waits for access to a
    shared resource. This process is called spinwaiting.

    A timeout causes a CPUSPINWAIT bugcheck.

    The default value is 100000 (100,000 10-microsecond intervals or
    1 second).

304  –  SMP_TICK_CNT

    SMP_TICK_CNT sets the frequency of sanity timer checks by each
    CPU in a multiprocessing system.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

305  –  SSI_ENABLE

    (Integrity servers only) This parameter controls the usage of
    system service interception. SSI_ENABLE is turned on by default.

    System Service Interception is a mechanism that allows user
    specified code to run before, after or instead of the intercepted
    system service. This mechanism is available on OpenVMS Alpha
    Version 6.1 and later and OpenVMS Integrity servers Version
    8.3 and later, but the parameter SSI_ENABLE is relevant only
    on Integrity server systems.

306  –  SSINHIBIT

    SSINHIBIT controls whether system services are inhibited (1)
    (on a per-process basis). By default, system services are not
    inhibited (0).

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

307  –  STARTUP_P1-8

    The following table describes possible values of STARTUP_P1
    through _P8:

    STARTUP
    Value          Description

    STARTUP_P1     Specifies the type of system boot the system-
                   independent startup procedure is to perform when
                   STARTUP_P1 has one of the following values:

                   o  " "- A full boot is performed.

                   o  "MIN"- A minimum boot that starts only what is
                      absolutely necessary for the operating system
                      to run.

    STARTUP_P2     Controls the setting of verification during the
                   execution of the system-independent startup
                   procedure, STARTUP.COM, when STARTUP_P2 has one
                   of the values described in the lists below.

                   STARTUP_P2 can be one of the values shown in the
                   following list:

                   o  F[ALSE], N[O], 0, " "-Verification is not
                      enabled; in other words, NOVERIFY is performed.

                   o  T[RUE], Y[ES], 1-Verification is enabled; in
                      other words, a SET VERIFY is performed.

                   Alternatively, STARTUP_P2 can be a string
                   containing one or more of the letters shown in
                   the following list:

                   o  C-Display various checkpointing messages during
                      startup.

                   o  D-Log (or Dump) the output from the startup to
                      a file called SYS$SPECIFIC:[SYSEXE]STARTUP.LOG.

                   o  P-DCL verification is enabled for each
                      component file, but not for the startup driver.
                      If both P and V are used, P is ignored.

                   o  V-Full DCL verification is enabled; same as
                      TRUE.

                   For more information about STARTUP_P2, see the
                   SYSMAN command STARTUP SET OPTIONS.
    STARTUP_P3     Beginning in OpenVMS Version 7.2, if STARTUP_P3
                   is set to AGEN, the system executes AUTOGEN at the
                   end of the startup sequence.

    STARTUP_P4     Reserved for future use.
    through
    STARTUP_P8

308  –  SWP_PRIO

    SWP_PRIO sets the priority of I/O transfers initiated by the
    swapper.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

309  –  SWPFAIL

    SWPFAIL sets the number of consecutive swap failures allowed
    before the swap schedule algorithm is changed to ignore the swap
    quantum protection.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

310  –  SWPOUTPGCNT

    This parameter allows the swapper an alternative mechanism before
    actually performing swaps.

    On Alpha and Integrity servers, SWPOUTPGCNT defines the minimum
    number of pagelets to which the swapper should attempt to reduce
    a process before swapping it out. The pagelets taken from the
    process are placed into the free-page list.

    SWPOUTPGCNT has the DYNAMIC attribute. On VAX systems,
    SWPOUTPGCNT also has the AUTOGEN attribute.

311  –  SWPRATE

    SWPRATE sets the swapping rate (in 10-millisecond units).
    This parameter limits the amount of disk bandwidth consumed by
    swapping.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

312  –  SYSMWCNT

    SYSMWCNT sets the quota for the size of the system working set,
    which contains the pageable portions of the system, the paged
    dynamic pool, RMS, and the resident portion of the system message
    file.

    While a high value takes space away from user working sets, a low
    value can seriously impair system performance. Appropriate values
    vary, depending on the level of system use. When the system is
    running at full load, check the rate of system faults with the
    MONITOR PAGE command of the Monitor utility. An average system
    page fault rate of between 0 and 3 page faults per second is
    desirable. If the system page fault rate is high, and especially
    if the system seems to be slow, you should increase the value of
    SYSMWCNT. However, do not set this parameter so high that system
    page faulting never occurs.

    SYSMWCNT has the AUTOGEN, GEN, and MAJOR attributes.

313  –  SYSPFC

    SYSPFC sets the number of pages to be read from disk on each
    system paging operation.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

314  –  SYSSER_LOGGING

    (Alpha and Integrity servers) A value of 1 for SYSSER_LOGGING
    enables logging of system service requests for a process. The
    default is 1.

    SYSSER_LOGGING is a DYNAMIC system parameter.

315  –  SYSTEM_CHECK

    SYSTEM_CHECK investigates intermittent system failures by
    enabling a number of run-time consistency checks on system
    operation and recording some trace information.

    Enabling SYSTEM_CHECK causes the system to behave as if the
    following system parameter values are set (although the values
    of the following parameters are not actually changed):

    Parameter        Value         Description

    BUGCHECKFATAL    1             Crash the system on nonfatal
                                   bugchecks.

    POOLCHECK        %X616400FF    Enable all poolchecking, with
                                   an allocated pool pattern
                                   of %x61616161 ('aaaa') and
                                   deallocated pool pattern of
                                   x64646464 ('dddd').

    MULTIPROCESSING  2             Enable full synchronization
                                   checking.

    While SYSTEM_CHECK is enabled, the previous settings of the
    BUGCHECKFATAL and MULTIPROCESSING parameters are ignored.
    However, setting the parameter POOLCHECK to a nonzero value
    overrides the setting imposed by SYSTEM_CHECK.

    Setting SYSTEM_CHECK creates certain image files that are capable
    of the additional system monitoring. These image files are
    located in SYS$LOADABLE_IMAGES and can be identified by the
    suffix _MON. For information about the type of data checking
    performed by SYSTEM_CHECK, see the description of the ACP_
    DATACHECK parameter. For information about the performance
    implications of enabling SYSTEM_CHECK, see OpenVMS Performance
    Management.

316  –  TAPE_ALLOCLASS

    TAPE_ALLOCLASS determines the tape allocation class for the
    system. The tape allocation class creates a unique clusterwide
    device name for multiple access paths to the same tape.

    The TAPE_ALLOCLASS parameter can also be used to generate a
    unique clusterwide name for tape devices with identical unit
    numbers.

317  –  TAPE_MVTIMEOUT

    TAPE_MVTIMEOUT is the time in seconds that a mount verification
    attempt continues on a given magnetic tape volume. If the mount
    verification does not recover the volume within that time, the
    I/O operations outstanding to the volume terminate abnormally.

    TAPE_MVTIMEOUT is a DYNAMIC parameter.

318  –  TBSKIPWSL

    TBSKIPWSL specifies the maximum number of working set list
    entries that may be skipped while scanning for a "good" entry
    to discard. Setting this parameter to 0 disables skipping.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

319  –  TIME_CONTROL

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

    TIME_CONTROL is an SMP bit mask parameter that controls debugging
    functions. The following bits are defined:

    Bit                    Description

    0                      Obsolete.

    1 (EXE$V_SANITY)       Disables the SMP sanity timer support.

    2 (EXE$V_NOSPINWAIT)   Disables the functional behavior of the
                           SMP spinwait support.

    TIME_CONTROL is a DYNAMIC parameter.

320  –  TIMEPROMPTWAIT

    TIMEPROMPTWAIT defines the number of seconds that you want a
    processor to wait for the time and date to be entered when a
    system boot occurs, if the processor's time-of-year clock does
    not contain a valid time. (The time unit of micro-fortnights
    is approximated as seconds in the implementation.) If the
    time specified by TIMEPROMPTWAIT elapses, the system continues
    the boot operation, and the date and time are set to the last
    recorded time that the system booted.

                                   NOTE

       VSI recommends that you set the correct system time before
       allowing the system to run, so that all functions using
       time-stamping (such as the operator log, the error log,
       accounting records, file creation dates, and file expiration
       dates) contain correct time values.

    Depending on the value specified for the TIMEPROMPTWAIT
    parameter, the system acts in one of the following ways:

    o  If TIMEPROMPTWAIT is 0, no prompt or wait occurs; the system
       boots immediately, using the time of the last boot as the
       system time.

    o  If TIMEPROMPTWAIT is a positive number less than 32768, one
       prompt is issued and the value dictates how many seconds you
       can take to respond with a time. If you do not provide a time
       before TIMEPROMPTWAIT elapses, the system boots, using the
       time of the last boot as the system time.

    o  If TIMEPROMPTWAIT is a number in the range of 32768 through
       65535, the prompt for the time is issued at intervals starting
       with 2 and doubling until 256 seconds is reached. If no
       response is received, the prompts restart, with the 2-second
       interval. This prompting process repeats indefinitely, until
       you specify a time.

321  –  TIMVCFAIL

    TIMVCFAIL specifies the time required for an adapter or virtual
    circuit failure to be detected. VSI recommends that the default
    value be used. VSI also recommends that this value be lowered only
    in OpenVMS Cluster of three CPUs or less, that the same value
    be used on each computer in the cluster, and that dedicated LAN
    segments be used for cluster I/O.

    TIMVCFAIL is a DYNAMIC parameter.

322  –  TMSCP_LOAD

    TMSCP_LOAD allows the loading of the tape mass storage control
    protocol server software. The TMSCP_LOAD parameter also sets
    locally connected tapes served. For information about setting the
    TMSCP_LOAD parameter, see VSI OpenVMS Cluster Systems.

    Setting TMSCP_LOAD to 0 inhibits the loading of the tape server
    and the serving of local tapes. Setting TMSCP to 1 loads the
    tape server into memory at the time the system is booted and
    makes all directly connected tape drives available clusterwide.
    The following table describes the two states of the TMSCP_LOAD
    parameter:

    State  Function

    0      Do not load the TMSCP tape server. Do not serve any local
           tape devices clusterwide. This is the default value.

    1      Load the TMSCP tape server. Serve all local TMSCP tape
           devices clusterwide.

    TMSCP_LOAD is an AUTOGEN parameter.

323  –  TMSCP_SERVE_ALL

    TMSCP_SERVE_ALL is a bit mask that controls the serving of tapes.
    The settings take effect when the system boots. You cannot change
    the settings when the system is running.

    Starting with OpenVMS Version 7.2, the serving types are
    implemented as a bit mask. To specify the type of serving your
    system will perform, locate the type you want in the following
    table and specify its value. For some systems, you may want
    to specify two serving types, such as serving all tapes except
    those whose allocation class does not match. To specify such a
    combination, add the values of each type, and specify the sum.

    In a mixed-version cluster that includes any systems running
    OpenVMS Version 7.1-x or earlier, serving all available tapes
    is restricted to serving all tapes except those whose allocation
    class does not match the system's allocation class (pre-Version
    7.2 meaning). To specify this type of serving, use the value 9,
    which sets bit 0 and bit 3. The following table describes the
    serving type controlled by each bit and its decimal value:

           Value
           When
    Bit    Set     Description

    Bit 0  1       Serve all available tapes (locally attached and
                   those connected to HSx and DSSI controllers).
                   Tapes with allocation classes that differ from the
                   system's allocation class (set by the ALLOCLASS
                   parameter) are also served if bit 3 is not set.

    Bit 1  2       Serve locally attached (non-HSx and non-DSSI)
                   tapes.

    Bit 2  N/A     Reserved.

    Bit 3  8       Restrict the serving specified by bit 0. All tapes
                   except those with allocation classes that differ
                   from the system's allocation class (set by the
                   ALLOCLASS parameter) are served.

                   This is pre-Version 7.2 behavior. If your cluster
                   includes systems running OpenVMS Version 7.1-x
                   or earlier, and you want to serve all available
                   tapes, you must specify 9, the result of setting
                   this bit and bit 0.

    Although the serving types are now implemented as a bit mask, the
    values of 0, 1, and 2, specified by bit 0 and bit 1, retain their
    original meanings:

    o  0 - Do not serve any tapes (the default for earlier versions
       of OpenVMS).

    o  1 - Serve all available tapes.

    o  2 - Serve only locally attached (non-HSx and non-DSSI) tapes.

    If the TMSCP_LOAD system parameter is 0, TMSCP_SERVE_ALL is
    ignored.

324  –  TTY_ALTALARM

    TTY_ALTALARM sets the size of the alternate type-ahead buffer
    alarm. This value indicates at what point an XOFF should be sent
    to terminals that use the alternate type-ahead buffers with the
    size specified by the TTY_ALTYPAHD parameter.

325  –  TTY_ALTYPAHD

    TTY_ALTYPAHD sets the size of the alternate type-ahead buffer.
    Use this parameter to allow the block mode terminals and
    communications lines to operate more efficiently.

    The default value is usually adequate. Do not exceed the maximum
    value of 32767 when setting this parameter.

326  –  TTY_AUTOCHAR

    TTY_AUTOCHAR sets the character the terminal driver echoes when
    the job controller has been notified.

    TTY_AUTOCHAR is a DYNAMIC parameter.

327  –  TTY_BUF

    TTY_BUF sets the default line width for terminals.

328  –  TTY_CLASSNAME

    TTY_CLASSNAME provides the 2-character prefix for the terminal
    class driver name that is required when booting. Changing the
    prefix can be useful when debugging a new terminal driver.

329  –  TTY_DEFCHAR

    TTY_DEFCHAR sets the default characteristics for terminals, using
    a code derived by summing the following hexadecimal values:

    Characteristic   Value (Hex)     Function

    PASSALL                 1        Passall.
    NOECHO                  2        Noecho mode.
    NOTYPEAHEAD             4        No type-ahead buffer.
    ESCAPE                  8        Escape sequence processing.
    HOSTSYNC               10        Host can send XON and XOFF.
    TTSYNC                 20        Terminal can send XON and XOFF.
    SCRIPT                 40        Internal use only.
    LOWER                  80        Lowercase.
    MECHTAB               100        Mechanical tabs.
    WRAP                  200        Wraparound at end of line.
    CRFILL                400        Perform carriage return fill.
    LFFILL                800        Perform line feed fill.
    SCOPE                1000        Terminal is a scope.
    REMOTE               2000        Internal use only.
    EIGHTBIT             8000        Eight-bit terminal.
    MBXDSABL            10000        Disable mailbox.
    NOBRDCST            20000        Prohibit broadcast.
    READSYNC            40000        XON and XOFF on reads.
    MECHFORM            80000        Mechanical form feeds.
    HALFDUP            100000        Set for half-duplex operation.
    MODEM              200000        Set for modem signals.
    PAGE             FF000000        Page size. Default is 24.

    Do not set the CRFILL or LRFILL characteristic as the default in
    TTY_DEFCHAR.

    Where a condition is false, the value is 0.

    The upper byte is the page length. The default characteristics
    are 24 lines per page, terminal synchronization, wraparound,
    lowercase, scope, and full-duplex.

330  –  TTY_DEFCHAR2

    TTY_DEFCHAR2 sets a second longword of default terminal
    characteristics. The default characteristics are represented
    as a code that is derived by summing the following hexadecimal
    values:

    Characteristic Value (Hex)   Function

    LOCALECHO             1      Enable local echo terminal logic;
                                 use with the TTY_DEFCHAR NOECHO
                                 characteristic.
    AUTOBAUD              2      Enable autobaud detection.
    HANGUP                4      Hang up on logout.
    MODHANGUP             8      Allow modification of HANGUP without
                                 privileges.
    BRDCSTMBX            10      Allow sending of broadcasts to
                                 mailboxes.
    XON                  20      (No effect in this parameter.)
    DMA                  40      (No effect in this parameter.)
    ALTYPEAHD            80      Use the alternate type-ahead
                                 parameters.
    SETSPEED            100      Clear to allow setting of speed
                                 without privileges.
    DCL_MAILBX          200      Function reserved for VSI use only.
    DECCRT4             400      Terminal is DIGITAL CRT Level 4.
    COMMSYNC            800      Enable flow control using modem
                                 signals.
    EDITING            1000      Line editing allowed.
    INSERT             2000      Sets default mode for insert.
    FALLBACK           4000      Do not set this bit with SYSGEN.
    DIALUP             8000      Terminal is a dialup line.
    SECURE            10000      Guarantees that no process is
                                 connected to terminal after Break
                                 key is pressed.
    DISCONNECT        20000      Allows terminal disconnect when a
                                 hangup occurs.
    PASTHRU           40000      Terminal is in PASTHRU mode.
    SYSPWD            80000      Log in with system password only.
    SIXEL            100000      Sixel graphics.
    DRCS             200000      Terminal supports loadable character
                                 fonts.
    PRINTER          400000      Terminal has printer port.
    APP_KEYPAD       800000      Notifies application programs of
                                 state to set keypad on exit.
    ANSICRT         1000000      Terminal conforms to ANSI CRT
                                 programming standards.
    REGIS           2000000      Terminal has REGIS CRT capabilities.
    BLOCK           4000000      Block mode terminal.
    AVO             8000000      Terminal has advanced video.
    EDIT           10000000      Terminal has local edit
                                 capabilities.
    DECCRT         20000000      Terminal is a DIGITAL CRT.
    DECCRT2        40000000      Terminal is a DIGITAL CRT Level 2.
    DECCRT3        80000000      Terminal is a DIGITAL CRT Level 3.

    The defaults are AUTOBAUD and EDITING.

331  –  TTY_DEFCHAR3

    (Alpha and Integrity servers) TTY_DEFCHAR3 allows a user to set a
    bit so that the OpenVMS terminal driver remaps CTRL/H to Delete.
    VSI recommends that you not set this bit as a systemwide default.

    Characteristic Value (Hex)   Function

    TT3$M_BS             10      When this bit is set, the OpenVMS
                                 terminal console remaps CTRL/H to
                                 Delete.

    For more information, see the SET TERM and SHOW TERM commands in
    the VSI OpenVMS DCL Dictionary.

332  –  TTY_DEFPORT

    TTY_DEFPORT provides flag bits for port drivers. Bit 0 set
    to 1 indicates that the terminal controller does not provide
    automatic XON/XOFF flow control. This bit should not be set for
    VSI Controllers, but it is needed for some foreign controllers.
    Currently only the YCDRIVER (DMF32, DMZ32) uses this bit.
    The remaining bits are reserved for future use. This special
    parameter should be modified only if recommended by VSI.

333  –  TTY_DIALTYPE

    TTY_DIALTYPE provides flag bits for dialups. Bit 0 is 1 for
    United Kingdom dialups and 0 for all others. Bit 1 controls the
    modem protocol used. Bit 2 controls whether a modem line hangs
    up 30 seconds after seeing CARRIER if a channel is not assigned
    to the device. The remaining bits are reserved for future use.
    See the OpenVMS I/O User's Reference Manual for more information
    about flag bits.

334  –  TTY_DMASIZE

    TTY_DMASIZE specifies a number of characters in the output
    buffer. Below this number, character transfers are performed;
    above this number, DMA transfers occur if the controller is
    capable of DMA I/O.

    TTY_DMASIZE is a DYNAMIC parameter.

335  –  TTY_PARITY

    TTY_PARITY sets terminal default parity.

336  –  TTY_RSPEED

    TTY_RSPEED defines the receive speed for terminals. If TTY_
    RSPEED is 0, TTY_SPEED controls both the transmit and the receive
    speed. Maximum value is 20. This parameter is only applicable for
    controllers that support split-speed operations, such as the DZ32
    and the DMF32.

337  –  TTY_SCANDELTA

    TTY_SCANDELTA sets the interval for polling terminals for dialup
    and hangup events. Shorter intervals use more processor time;
    longer intervals may result in missing a hangup event.

338  –  TTY_SILOTIME

    TTY_SILOTIME defines the interval at which the DMF32 hardware
    polls the input silo for received characters. The DMF32
    asynchronous terminal controller can delay the generation
    of a single input interrupt until multiple characters have
    accumulated in the input silo. TTY_SILOTIME specifies the number
    of milliseconds that the characters are allowed to accumulate
    prior to the generation of an input interrupt by the hardware.

                                   NOTE

       The remainder of this discussion is of interest to customers
       who use Digi Edgeport hardware.

    TTY_SILOTIME controls latency, trading throughput and system
    overhead for latency. The default value for TTY_SILOTIME is 8.
    This value is multiplied by 100 and is used as a count of the
    number of times to send a query to the device for more data after
    a character transmit or receive is performed.

    If no input (or no subsequent output) is seen after 800 responses
    to the query, the driver stops sending queries to the device and
    waits for an input interrupt. Reducing the TTY_SILOTIME value
    allows the device to buffer more data, with slightly higher
    latency.

    Increasing the value of TTY_SILOTIME makes the device more
    sensitive to latency but decreases buffering and overall
    throughput; it also adds more system and USB overhead. Setting
    TTY_SILOTIME to zero causes the driver to send input queries to
    the device continually. This setting causes the lowest latency,
    the highest system overhead, and the lowest throughput possible.

339  –  TTY_SPEED

    TTY_SPEED sets the systemwide default speed for terminals. Low
    byte is transmit speed, and high byte is receive speed. If high
    byte is set to 0, receive speed is identical to transmit speed.
    Maximum value is 20. Baud rates are defined by the $TTDEF macro.

340  –  TTY_TIMEOUT

    TTY_TIMEOUT sets the number of seconds before a process
    associated with a disconnected terminal is deleted. The default
    value (900 seconds) is usually adequate. Note that using values
    for TTY_TIMEOUT greater than one year (value %X01E13380) can
    cause overflow errors and result in a disconnected device timing
    out immediately.

    TTY_TIMEOUT is a DYNAMIC parameter.

341  –  TTY_TYPAHDSZ

    TTY_TYPAHDSZ sets the size of the terminal type-ahead buffer.
    The default value is usually adequate. Do not exceed the maximum
    value of 32767 when setting this parameter.

342  –  UAFALTERNATE

    UAFALTERNATE enables or disables the assignment of SYSUAF
    as the logical name for SYSUAFALT, causing all references
    to the user authorization file (SYSUAF) to be translated to
    SYS$SYSTEM:SYSUAFALT. Use of the normal user authorization file
    (SYS$SYSTEM:SYSUAF) can be restored by deassigning the system
    logical name SYSUAF. This parameter should be set on (1) only
    when the system is being used by a restricted set of users. You
    must create a user authorization file named SYSUAFALT prior to
    setting UAFALTERNATE to 1.

    UAFALTERNATE has the GEN and MAJOR attributes.

343  –  USERD1

    USERD1 is reserved for definition at the user's site. The
    reserved longword is referenced by the symbol SGN$GL_USERD1.

    On Alpha and Integrity servers, this symbol is in the
    SYS$LOADABLE_IMAGES:SYS$BASE_IMAGE module.

    USERD1 is a DYNAMIC parameter.

344  –  USERD2

    USERD2 is reserved for definition at the user's site. The
    reserved longword is referenced by the symbol SGN$GL_USERD2.

    On Alpha and Integrity servers, this symbol is in the
    SYS$LOADABLE_IMAGES:SYS$BASE_IMAGE module.

    USERD2 is a DYNAMIC parameter.

345  –  USER3

    USER3 is a parameter that is reserved for definition at the
    user's site. The reserved longword is referenced by the symbol
    SGN$GL_USER3.

    On Alpha and Integrity servers, this symbol is in the
    SYS$LOADABLE_IMAGES:SYS$BASE_IMAGE module.

346  –  USER4

    USER4 is a parameter that is reserved for definition at the
    user's site. The reserved longword is referenced by the symbol
    SGN$GL_USER4.

    On Alpha and Integrity servers, this symbol is in the
    SYS$LOADABLE_IMAGES:SYS$BASE_IMAGE module.

347  –  VAXCLUSTER

    VAXCLUSTER controls loading of the cluster code. Specify one of
    the following:

    Value  Description

    0      Never form or join a cluster.

    1      Base decision of whether to form (or join) a cluster or to
           operate standalone on the presence of cluster hardware.

    2      Always form or join a cluster.

    The default value is 1.

    VAXCLUSTER is an AUTOGEN parameter.

348  –  VCC_FLAGS

    (Alpha only) The static system parameter VCC_FLAGS enables and
    disables file system data caching. If caching is enabled, VCC_
    FLAGS controls which file system data cache is loaded during
    system startup.

    Value  Description

    0      Disables file system data caching on the local node and
           throughout the OpenVMS Cluster.

           In an OpenVMS Cluster, if caching is disabled on any node,
           none of the other nodes can use the extended file cache
           or the virtual I/O cache. They can't cache any file data
           until that node either leaves the cluster or reboots with
           VCC_FLAGS set to a nonzero value.

    1      Enables file system data caching and selects the Virtual
           I/O Cache. This is the default for VAX systems.

    2      Enables file system data caching and selects the extended
           file cache. This is the default for Alpha systems.

                                   NOTE

       On Integrity servers, the volume caching product
       ([SYS$LDR]SYS$VCC.EXE) is not available. XFC caching is the
       default caching mechanism. Setting the VCC_FLAGS parameter
       to 1 is equivalent to not loading caching at all or to
       setting VCC_FLAGS to 0.

    VCC_FLAGS is an AUTOGEN parameter.

349  –  VCC_MAXSIZE

    (Alpha and Integrity servers) The static system parameter VCC_
    MAXSIZE controls the size of the virtual I/O cache. VCC_MAXSIZE,
    which specifies the size in blocks, is 3,700,000 by default.

    The virtual I/O cache cannot shrink or grow. Its size is fixed at
    system startup.

    To adjust the XFC size, use the VCC_MAX_CACHE system parameter.

    VCC_MAXSIZE is an AUTOGEN parameter.

350  –  VCC_MAX_CACHE

    (Alpha and Integrity servers) The dynamic system parameter VCC_
    MAX_CACHE controls the maximum size of the extended file cache.
    It specifies the size in megabytes. By default, VCC_MAX_CACHE has
    a special value of -1 for people who do not want to tune their
    systems manually; this value means that at system startup, the
    maximum size of the extended file cache is set to 50 percent of
    the physical memory on the system.

    The extended file cache can automatically shrink and grow,
    depending on your I/O workload and how much spare memory
    your system has. As your I/O workload increases, the cache
    automatically grows, but never to more than the maximum size.
    When your application needs memory, the cache automatically
    shrinks.

    The value of VCC_MAX_CACHE at system startup sets an upper limit
    for the maximum size of the extended file cache. You cannot
    increase the maximum size of VCC_MAX_CACHE beyond its value
    at boot time. For example, if VCC_MAX_CACHE is 60 MB at system
    startup, you can then set VCC_MAX_CACHE to 40, which decreases
    the maximum size to 40 MB. If you then set VCC_MAX_CACHE to 80,
    the maximum size is only increased to 60 MB, the value set at
    system startup.

    Note that VCC_MAX_CACHE is a semi-dynamic parameter. If you
    change its value, you must enter the DCL command SET CACHE/RESET
    for any changes to take effect immediately. Otherwise, it might
    take much more time for the changes to take effect.

    If you are using the reserved memory registry to allocate
    memory permanently, you must set the VCC$MIN_CACHE_SIZE entry
    in the reserved memory registry to a value less than or equal to
    VCC_MAX_CACHE at system startup time.

    For instructions on setting permanent memory allocations for the
    cache, see the VSI OpenVMS System Manager's Manual.

    VCC_MAX_CACHE is a DYNAMIC parameter.

351  –  VCC_MAX_IO_SIZE

    (Alpha and Integrity servers) The dynamic system parameter VCC_
    MAX_IO_SIZE controls the maximum size of I/O that can be cached
    by the extended file cache. It specifies the size in blocks. By
    default, the size is 127 blocks.

    Changing the value of VCC_MAX_IO_SIZE affects reads and writes to
    volumes currently mounted on the local node, as well as reads and
    writes to volumes mounted in the future.

    If VCC_MAX_IO_SIZE is 0, the extended file cache on the local
    node cannot cache any reads or writes. However, the system is
    not prevented from reserving memory for the extended file cache
    during startup if a VCC$MIN_CACHE_SIZE entry is in the reserved
    memory registry.

    VCC_MAX_IO_SIZE is a DYNAMIC parameter.

352  –  VCC_MAX_LOCKS

    (Alpha and Integrity servers) VCC_MAX_LOCKS is a special
    parameter reserved for VSI use only. Extended file cache will
    use this parameter in future versions.

353  –  VCC_PAGESIZE

    (Alpha and Integrity servers) VCC_PAGESIZE is a special parameter
    reserved for VSI use only. Extended file cache will use this
    parameter in future versions.

354  –  VCC_READAHEAD

    (Alpha and Integrity servers) The dynamic system parameter VCC_
    READAHEAD controls whether the extended file cache can use read-
    ahead caching. Read-ahead caching is a technique that improves
    the performance of applications that read data sequentially.

    By default VCC_READAHEAD is 1, which means that the extended file
    cache can use read-ahead caching. The extended file cache detects
    when a file is being read sequentially in equal-sized I/Os, and
    fetches data ahead of the current read, so that the next read
    instruction can be satisfied from cache.

    To stop the extended file cache from using read-ahead caching,
    set VCC_READAHEAD to 0.

    Changing the value of VCC_READAHEAD affects volumes currently
    mounted on the local node, as well as volumes mounted in the
    future.

    Readahead I/Os are totally asynchronous from user I/Os and only
    take place if sufficient system resources are available.

    VCC_READAHEAD is a DYNAMIC parameter.

355  –  VCC_RSVD

    (Alpha and Integrity servers) VCC_RSVD is a special parameter
    reserved for VSI use only. Extended file cache will use this
    parameter in future versions.

356  –  VCC_WRITEBEHIND

    (Alpha and Integrity servers) VCC_WRITEBEHIND is reserved for VSI
    use only. Extended file cache will use this parameter in future
    versions.

357  –  VCC_WRITE_DELAY

    (Alpha and Integrity servers) VCC_WRITE_DELAY is reserved for VSI
    use only.

358  –  VHPT_SIZE

    (Integrity servers only) VHPT_SIZE is the number of kilobytes to
    allocate for the virtual hash page table (VHPT) on each CPU in
    the system:

    o  0 indicates that no VHPT is allocated.

    o  1 indicates that OpenVMS is to choose a default size that is
       appropriate for your system configuration.

    If a VHPT is created, the smallest size is 32KB. The VHPT_SIZE
    must be a power of 2 KB in size. If the number specified is not
    a power of 2, OpenVMS chooses a VHPT size to use for your system
    that is close to the number specified.

    If insufficient memory is available during system startup,
    OpenVMS might choose a smaller size for the VHPT of each CPU.

    A summary of possible values for VHPT_SIZE is in the following
    table:

    Value Description

    0     Do not create a VHPT on each CPU.
    1     (default) OpenVMS chooses a VHPT of an appropriate size for
          each CPU.
    n     Create a VHPT of nKB for each CPU, where n is a power of
          2 that is 32 or greater. (The maximum value, however, is
          platform-dependent.)

359  –  VIRTUALPAGECNT

    On VAX systems, VIRTUALPAGECNT sets the maximum number of virtual
    pages that can be mapped for any one process. A program is
    allowed to divide its virtual space between the P0 and P1 tables
    in any proportion.

    If you use SYS$UPDATE:LIBDECOMP.COM to decompress libraries
    and the VIRTUALPAGECNT setting is low, make sure you set the
    PGFLQUOTA field in the user authorization file to at least twice
    the size of the library.

    At installation time, AUTOGEN automatically sets an appropriate
    value for VIRTUALPAGECNT. The value depends on the particular
    configuration-the type and number of graphics adapters on the
    system, if any exist. You cannot set VIRTUALPAGECNT below the
    minimum value required for your graphics configuration.

    Because the VIRTUALPAGECNT setting supports hardware address
    space rather than system memory, do not use the value of
    VIRTUALPAGECNT that AUTOGEN sets to gauge the size of your page
    file.

    Starting with OpenVMS Version 7.0, VIRTUALPAGECNT has been an
    obsolete parameter on Alpha systems. Note, however, that the
    parameter remains in existence on Alpha and Integrity servers
    for compatibility purposes and has a default and maximum value of
    %X7FFFFFFF. SYSBOOT and AUTOGEN enforce this default value.

    VIRTUALPAGECNT has the AUTOGEN, GEN, and MAJOR attributes.

360  –  VMS1-8

    VMSD1, VMSD2, VMSD3, VMSD4, VMS5, VMS6, VMS7, and VMS8 are
    special parameters reserved for VSI use. VMSD1 through VMSD4 are
    DYNAMIC.

361  –  VOTES

    VOTES establishes the number of votes an OpenVMS Cluster member
    system contributes to a quorum.

    VOTES has the AUTOGEN attribute.

362  –  WBM_MSG_INT

    WBM_MSG_INT is one of three system parameters that are available
    for managing the update traffic between a master write bitmap
    and its corresponding local write bitmaps in an OpenVMS Cluster
    system. The others are WBM_MSG_UPPER and WBM_MSG_LOWER. These
    parameters set the interval at which the frequency of sending
    messages is tested and also set an upper and lower threshold that
    determine whether the messages are grouped into one SCS message
    or are sent one by one.

    In single-message mode, WBM_MSG_INT is the time interval in
    milliseconds between assessments of the most suitable write
    bitmap message mode. In single-message mode, the writes issued by
    each remote node are, by default, sent one by one in individual
    SCS messages to the node with the master write bitmap. If
    the writes sent by a remote node reach an upper threshhold
    of messages during a specified interval, single-message mode
    switches to buffered-message mode.

    In buffered-message mode, WBM_MSG_INT is the maximum time a
    message waits before it is sent. In buffered-message mode, the
    messages are collected for a specified interval and then sent
    in one SCS message. During periods of increased message traffic,
    grouping multiple messages to send in one SCS message to the
    master write bitmap is generally more efficient than sending each
    message separately.

    The minimum value of WBM_MSG_INT is 10 milliseconds. The maximum
    value is -1, which corresponds to the maximum positive value that
    a longword can represent. The default is 10 milliseconds.

    WBM_MSG_INT is a DYNAMIC parameter.

363  –  WBM_MSG_LOWER

    WBM_MSG_LOWER is one of three system parameters that are
    available for managing the update traffic between a master
    write bitmap and its corresponding local write bitmaps in an
    OpenVMS Cluster system. The others are WBM_MSG_INT and WBM_MSG_
    UPPER. These parameters set the interval at which the frequency
    of sending messages is tested and also set an upper and lower
    threshold that determine whether the messages are grouped into
    one SCS message or are sent one by one.

    WBM_MSG_LOWER is the lower threshold for the number of messages
    sent during the test interval that initiates single-message mode.
    In single-message mode, the writes issued by each remote node
    are, by default, sent one by one in individual SCS messages to
    the node with the master write bitmap. If the writes sent by
    a remote node reach an upper threshhold of messages during a
    specified interval, single-message mode switches to buffered-
    message mode.

    The minimum value of WBM_MSG_LOWER is 0 messages per interval.
    The maximum value is -1, which corresponds to the maximum
    positive value that a longword can represent. The default is
    10.

    WBM_MSG_LOWER is a DYNAMIC parameter.

364  –  WBM_MSG_UPPER

    WBM_MSG_UPPER is one of three system parameters that are
    available for managing the update traffic between a master
    write bitmap and its corresponding local write bitmaps in an
    OpenVMS Cluster system. The others are WBM_MSG_INT and WBM_MSG_
    LOWER. These parameters set the interval at which the frequency
    of sending messages is tested and also set an upper and lower
    threshold that determine whether the messages are grouped into
    one SCS message or are sent one by one.

    WBM_MSG_UPPER is the upper threshold for the number of messages
    sent during the test interval that initiates buffered-message
    mode. In buffered-message mode, the messages are collected for a
    specified interval and then sent in one SCS message.

    The minimum value of WBM_MSG_UPPER is 0 messages per interval.
    The maximum value is -1, which corresponds to the maximum
    positive value that a longword can represent. The default is
    100 seconds.

    WBM_MSG_UPPER is a DYNAMIC parameter.

365  –  WBM_OPCOM_LVL

    WBM_OPCOM_LVL controls whether write bitmap system messages are
    sent to the operator console. Possible values are shown in the
    following table:

    Value Description

    0     Messages are turned off.

    1     The default; messages are provided when write bitmaps are
          started, deleted, and renamed, and when the SCS message
          mode (buffered or single) changes.

    2     All messages for a setting of 1 are provided plus many
          more.

    WBM_OPCOM_LVL is a DYNAMIC parameter.

366  –  WINDOW_SYSTEM

    WINDOW_SYSTEM specifies the windowing system to be used on a
    workstation. Specify one of the following values:

    Value  Description

    1      Load the DECwindows Motif for OpenVMS workstation
           environment.

    2      Load the UIS workstation environment.

    WINDOW_SYSTEM is a DYNAMIC parameter.

367  –  WLKSYSDSK

    (Alpha and Integrity servers) WLKSYSDSK is used by various
    bootstrap components to determine if the system disk should be
    treated as though it is write-locked. This parameter is used
    primarily to allow OpenVMS to boot from a CD.

368  –  WPRE_SIZE

    WPRE_SIZE represents the number of pages to be allocated to
    accommodate WatchPoint Recovery Entries (WPRE) on the Watchpoint
    Driver.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

    WPRE_SIZE is a DYNAMIC parameter.

369  –  WPTTE_SIZE

    WPTTE_SIZE is the number of entries that the WPDRIVER creates in
    the WatchPoint Trace Table.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

    WPTTE_SIZE is a DYNAMIC parameter.

370  –  WRITABLESYS

    WRITABLESYS controls whether system code is writable. This
    parameter is set (value of 1) for debugging purposes only.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

371  –  WRITESYSPARAMS

    On Alpha and Integrity servers, WRITESYSPARAMS indicates that
    parameters are modified during SYSBOOT and are written out to
    ALPHAVMSSYS.PAR by STARTUP.COM.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

    WRITESYSPARAMS is a DYNAMIC parameter.

372  –  WSDEC

    Increasing the value of this parameter tends to increase the
    speed with which working set limits are decreased when the need
    arises.

    On Alpha and Integrity servers, WSDEC specifies the number of
    pagelets by which the limit of a working set is automatically
    decreased at each adjustment interval (which is quantum end). At
    a setting of 35, for example, the system decreases the limit of a
    working set by 35 pagelets each time a decrease is required.

    WSDEC has the AUTOGEN, DYNAMIC, and MAJOR attributes.

373  –  WSINC

    Decreasing the value of this parameter tends to reduce the speed
    with which working set limits are increased when the need arises.
    Normally, you should keep this parameter at a high value because
    a rapid increase in limit is often critical to performance.

    On Alpha and Integrity servers, WSINC specifies the number of
    pagelets by which the limit of a working set is automatically
    increased at each adjustment interval (which is quantum end). At
    a setting of 150, for example, the system increases the limit of
    a working set by 150 pagelets each time an increase is required.
    On Alpha and Integrity servers, the default value is 2400 512-
    byte pagelets (150 8192-byte Alpha and Integrity server pages).

    A value of 0 for WSINC disables the automatic adjustment of
    working set limits for all processes. Limits stay at their base
    values. You can disable the automatic adjustment of working
    set limits on a per-process basis by using the DCL command SET
    WORKING_SET.

    WSINC has the DYNAMIC and MAJOR attributes. On Alpha and
    Integrity servers, WSINC also has the AUTOGEN attribute.

374  –  WSMAX

    WSMAX sets the maximum number of pages on a systemwide basis for
    any working set. WSMAX is calculated as a quarter of the first
    32 MB plus a sixteenth of the memory from 32 to 256 MB, plus a
    sixty-fourth of the memory (if any) above 256 MB.

    This is intended to assist managers of systems that host large
    numbers of users whose working sets are not large. Systems whose
    user bases consist of a small number of users (or processes)
    that require large amounts of physical memory (for example,
    simulations) might need to set MIN_WSMAX to a value that
    satisfies the requirements of those processes.

    WSMAX has the AUTOGEN, GEN, and MAJOR attributes.

375  –  XQPCTL2

    XQPCTL2 controls improved concurrency. The default value of
    XQPCTL2 is 1, which turns on improved concurrency. Setting
    XQPCTL2 to 0 turns off improved concurrency. This parameter
    affects local access to the extent and file ID caches.

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

376  –  XQPCTLD1

    XQPCTLD1 controls multithreading, which can be used only
    by PATHWORKS servers. The default value of XQPCTLD1 is 8,
    which enables multithreading. Setting XQPCTLD1 to 0 disables
    multithreading,

    This special parameter is use by VSI and is subject to change. Do
    not change this parameter unless VSI recommends that you do so.

377  –  ZERO_LIST_HI

    (Alpha and Integrity servers) ZERO_LIST_HI is the maximum number
    of pages zeroed and put on the zeroed page list. This list is
    used as a cache of pages containing all zeros, which improves the
    performance of allocating such pages.

    ZERO_LIST_HI has the AUTOGEN and DYNAMIC attributes.
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