Displays the availability and usage of those system resources
that are related to memory.
Format
SHOW MEMORY
1 – Qualifiers
1.1 /ALL
/ALL (default)
Displays all available information, that is, information
displayed by the /FILES, /PHYSICAL_PAGES, /POOL, and /SLOTS
qualifiers.
1.2 /BITMAP
/BITMAP (Alpha/Integrity servers only)
Displays information about memory use by write bitmaps (WBM) used
with Host-Based Volume Shadowing (HBVS). If the system parameter
SHADOWING is set to 0, no information about bitmaps is displayed
because WBM is used only with HBVS.
Note that the memory consumption displayed by SHOW MEMORY is
often greater than that displayed by SHOW DEVICE /BITMAP, which
displays the exact size (in bytes) of the bitmap. The memory used
by a bitmap is allocated in units of pages; if a bitmap uses part
of a page of memory, the rest of that page is unavailable for
use.
1.3 /BUFFER_OBJECTS
/BUFFER_OBJECTS (Alpha/Integrity servers only)
Displays information about system resources used by buffer
objects.
1.4 /CACHE
/CACHE[=(keyword[,...])]
Displays information about the Virtual I/O Cache facility or
the Extended File Cache facility, depending on which is loaded.
The Cache facility information is displayed as part of the SHOW
MEMORY and SHOW MEMORY/CACHE/FULL commands.
If the Extended File Cache is loaded, you can specify the
following keywords and options:
VOLUME[=device] Requests display of volume-level statistics
for the specified volume(s). If no device
is specified, defaults to SYS$DISK. Device
specifications may be wildcarded; if so, the
device specification must be based on the
physical device name. Specify VOLUME=* to see
statistics for all volumes in cache.
FILE=filespec Requests display of file-level statistics for
the specified file(s) in cache. The filespec
must contain an explicit or implicit device
specification. The filespec may be wildcarded
according to RMS rules. Specify FILE=dev:*.*
to see statistics for all files in cache for a
device. Partially wild file specifications that
are satisfied by large numbers of files on disk
may incur significant processing overhead during
display. By default, both open and closed files
are displayed (use the OPEN and CLOSED keywords
to further restrict which files are displayed).
Note that this command may fail if you select a
large number of files for display. If you receive
an error message, reduce the number of selected
files and reissue the command.
TOPQIO[=n] Requests display of file-level statistics for
the n files in cache with the highest overall QIO
count (n defaults to 10).
TOPHITRATE[=n] Requests display of file-level statistics for the
n files in cache with the highest overall cache
hit rate (n defaults to 10).
OPEN Include only open files in the display
(default for TOPQIO and TOPHITRATE).
CLOSED Include only closed files in the
display.
1.5 /EXACT
Use with the /PAGE=SAVE and /SEARCH qualifiers to specify a
search string that must match the search string exactly and must
be enclosed with quotation marks (" ").
If you specify the /EXACT qualifier without the /SEARCH
qualifier, exact search mode is enabled when you set the search
string with the Find (E1) key.
1.6 /FILES
Displays information about the use of each paging and swapping
file currently installed.
1.7 /FULL
When used with /POOL, displays additional information about pool
area.
When used with /CACHE, displays additional information about the
file data cache that is loaded (either VIOC or XFC).
This qualifier is ignored unless the /CACHE or /POOL qualifier is
specified explicitly.
1.8 /GH_REGIONS
On Alpha, displays information about the granularity hint regions
(GHR) that have been established. For each of these regions,
information is displayed about the size of the region, the amount
of free memory, the amount of memory in use, and the amount of
memory released to OpenVMS from the region. The granularity hint
regions information is also displayed as part of SHOW MEMORY,
SHOW MEMORY/ALL, and SHOW MEMORY/FULL commands.
1.9 /HIGHLIGHT
/HIGHLIGHT[=keyword]
Use with the /PAGE=SAVE and /SEARCH qualifiers to specify the
type of highlighting you want when a search string is found. When
a string is found, the entire line is highlighted. You can use
the following keywords: BOLD, BLINK, REVERSE, and UNDERLINE. BOLD
is the default highlighting.
1.10 /OUTPUT
/OUTPUT[=filespec]
/NOOUTPUT
Controls where the output of the command is sent. If you do
not enter the qualifier, or if you enter the /OUTPUT qualifier
without a file specification, the output is sent to the current
process default output stream or device, identified by the
logical name SYS$OUTPUT.
If you enter the /OUTPUT qualifier with a partial file
specification (for example, specifying only a directory), SHOW
is the default file name and .LIS the default file type. If you
enter a file specification, it cannot include asterisk (*) and
the percent sign (%) wildcard characters.
If you enter the /NOOUTPUT qualifier, output is suppressed.
1.11 /PAGE
/PAGE[=keyword]
/NOPAGE (default)
Controls the display of memory information on the screen.
You can use the following keywords with the /PAGE qualifier:
CLEAR_SCREEN Clears the screen before each page is displayed.
SCROLL Displays information one line at a time.
SAVE[=n] Enables screen navigation of information, where n
is the number of pages to store.
The /PAGE=SAVE qualifier allows you to navigate through screens
of information. The /PAGE=SAVE qualifier stores up to 5 screens
of up to 255 columns of information. When you use the /PAGE=SAVE
qualifier, you can use the following keys to navigate through the
information:
Key Sequence Description
Up arrow key, Ctrl/B Scroll up one line.
Down arrow key Scroll down one line.
Left arrow key Scroll left one column.
Right arrow key Scroll right one column.
Find (E1) Specify a string to find when the
information is displayed.
Insert Here (E2) Scroll right one half screen.
Remove (E3) Scroll left one half screen.
Select (E4) Toggle 80/132 column mode.
Prev Screen (E5) Get the previous page of information.
Next Screen (E6), Get the next page of information.
Return, Enter, Space
F10, Ctrl/Z Exit. (Some utilities define these
differently.)
Help (F15) Display utility help text.
Do (F16) Toggle the display to oldest/newest
page.
Ctrl/W Refresh the display.
The /PAGE qualifier is not compatible with the /OUTPUT qualifier.
1.12 /PHYSICAL_PAGES
Displays information about the amount of physical memory and the
number of free and modified pages.
1.13 /POOL
Displays information about the usage of each dynamic memory
(pool) area, including the amount of free space and the size
of the largest contiguous block in each area.
1.14 /RESERVED
/RESERVED (Alpha/Integrity servers only)
Displays information about memory reservations.
1.15 /SEARCH
/SEARCH="string"
Use with the /PAGE=SAVE qualifier to specify a string that you
want to find in the information being displayed. Quotation marks
are required for the /SEARCH qualifier, if you include spaces in
the text string.
You can also dynamically change the search string by pressing the
Find key (E1) while the information is being displayed. Quotation
marks are not required for a dynamic search.
1.16 /SLOTS
Displays information about the availability of partition control
block (PCB) vector slots and balance slots.
1.17 /UNITS
/UNITS=keyword
Allows you to override the current default specified by SET
PROCESS/UNITS so that you can display memory in your choice of
blocks or bytes.
Keyword options are:
Option Description
BLOCKS Displays memory in blocks (equivalent to PAGES).
BYTES Displays memory in bytes.
PAGES Displays memory in page format (equivalent to
BLOCKS).
1.18 /WRAP
/WRAP
/NOWRAP (default)
Use with the /PAGE=SAVE qualifier to limit the number of columns
to the width of the screen and to wrap lines that extend beyond
the width of the screen to the next line.
The /NOWRAP qualifier extends lines beyond the width of the
screen and can be seen when you use the scrolling (left and
right) features provided by the /PAGE=SAVE qualifier.
2 – Examples
1.$ SHOW MEMORY
System Memory Resources on 20-JAN-2001 15:22:04.11
Physical Memory Usage (pages): Total Free In Use Modified
Main Memory (2.00Gb) 262144 201249 60162 733
Extended File Cache (Time of last reset: 18-JAN-2001 17:15:14.33)
Allocated (Mbytes) 370.00 Maximum size (Mbytes) 1024.00
Free (Mbytes) 317.79 Minimum size (Mbytes) 370.00
In use (Mbytes) 52.20 Percentage Read I/Os 72%
Read hit rate 96% Write hit rate 0%
Read I/O count 119363 Write I/O count 46259
Read hit count 115283 Write hit count 0
Reads bypassing cache 45 Writes bypassing cache 0
Files cached open 372 Files cached closed 392
Vols in Full XFC mode 0 Vols in VIOC Compatible mode 3
Vols in No Caching mode 0 Vols in Perm. No Caching mode 0
Granularity Hint Regions (pages): Total Free In Use Released
Execlet code region 1024 0 586 438
Execlet data region 256 0 256 0
S0/S1 Executive data region 576 0 576 0
Resident image code region 1024 0 830 194
Slot Usage (slots): Total Free Resident Swapped
Process Entry Slots 647 614 33 0
Balance Set Slots 645 614 31 0
Dynamic Memory Usage: Total Free In Use Largest
Nonpaged Dynamic Memory (Mb) 4.28 2.38 1.89 2.25
Bus Addressable Memory (Kb) 168.00 128.00 40.00 128.00
Paged Dynamic Memory (Mb) 5.68 3.42 2.26 3.41
Lock Manager Dyn Memory (Mb) 1.13 0.00 1.12
Buffer Object Usage (pages): In Use Peak
32-bit System Space Windows (S0/S1) 3 3
64-bit System Space Windows (S2) 0 0
Physical pages locked by buffer objects 3 3
Memory Reservations (pages): Group Reserved In Use Type
VCC$MIN_CACHE_SIZE --- 47360 47360 Allocated
Total (370.00 Mbytes reserved) 47360 47360
Swap File Usage (8KB pages): Index Free Size
DISK$X6XV_BRAHMA:[SYS0.SYSEXE]SWAPFILE.SYS
1 5168 5168
Paging File Usage (8KB pages): Index Free Size
DISK$X6XV_BRAHMA:[SYS0.SYSEXE]PAGEFILE.SYS
254 215288 215288
Total committed paging file usage: 7418
Of the physical pages in use, 4951 pages are permanently allocated to
OpenVMS.
This example shows reservable pages. If the reservable pages
are a negative value, this indicates that you may want
to consider adding to the fixed amount of pagefile space
available.
2.$ SHOW MEMORY/CACHE/FULL
System Memory Resources on 3-NOV-2001 18:36:12.79
Extended File Cache (Time of last reset: 31-OCT-2001 10:18:07.39)
Allocated (Mbytes) 1370.00 Maximum size (Mbytes) 91024.00
Free (Mbytes) 2319.75 Minimum size (Mbytes) 10 370.0
In use (Mbytes) 3 50.25 Percentage Read I/Os 11 98%
Read hit rate 4 79% Write hit rate 12 0%
Read I/O count 5 18110 Write I/O count 13 310
Read hit count 6 14343 Write hit count 14 0
Reads bypassing cache 7 37 Writes bypassing cache 15 0
Files cached open 8 351 Files cached closed 16 307
Vols in Full XFC mode 17 0 Vols in VIOC Compatible mode 17 0
Vols in No Caching mode17 0 Vols in Perm No Caching mode 17 0
I/O Statistics 18 - Distributions (MAX_IO_SIZE: 127 19)
-------------------------------------------------------
Transfer Size: Reads Read Hits Writes
1 Block IO: 35053 20 34553 21 87 22
2 Block IO: 469 284 9
3 Block IO: 26516 26346 24
4 Block IO: 348 205 6
5 Block IO: 13205 13160 0
6 Block IO: 161 111 0
7 Block IO: 185 152 0
.
.
.
114 Block IO: 1 0 0
116 Block IO: 2 1 0
121 Block IO: 1 0 0
>127<256 Block IO: 12 0
>255 Block IO: 14 0
----------------------------------------------------
Totals: 84411 80535 630
NOTE
This example shows the output for the SHOW MEMORY/CACHE/FULL
command on an Alpha system with the Extended File Cache
loaded. The SHOW MEMORY/CACHE/FULL command will display
different fields on an Alpha system with the Virtual I/O
Cache loaded.
Extended File Cache Usage
Shows the use of the Extended File Cache facility on an Alpha
system.
1 Allocated Total amount of system memory in megabytes
allocated to the Extended File Cache.
2 Free Number of allocated megabytes not currently
in use by the cache.
3 In use Number of allocated megabytes that contain
valid cached data.
4 Read hit rate Shows cache read hits as a percentage of
read I/Os.
5 Read I/O count Total number of read I/Os that have been
seen by the cache since the last statistics
reset.
6 Read hit count Total number of read I/Os that did not
perform a physical I/O, because the data
for these was found in the cache since the
prior statistics reset.
7 Reads bypassing Total number of reads that bypassed the
cache cache and went directly to disk since the
last statistics reset.
8 Files cached Total number of open files in cache.
open
9 Maximum size Maximum size of the cache in megabytes.
(Mbytes)
10 Minimum size Minimum size of the cache in megabytes.
(Mbytes) This displays the value of the memory
reservation, VCC$MIN_CACHE_SIZE. See the
VSI OpenVMS System Manager's Manual for
additional information.
11 Percentage Percentage of read I/Os that occur. For
Read I/Os example, a read/write I/O ratio of 100%
implies that all were read I/Os.
12 Write hit rate (Always zero for Extended File Cache,
Version 1.)
13 Write I/O Total number of write I/Os that have been
count seen by the cache since the last statistics
reset.
14 Write hit (Always zero for Extended File Cache,
count Version 1.)
15 Writes Total number of writes that bypassed the
bypassing cache cache and went directly to disk since the
last statistics reset.
16 Files cached Total number of closed files in cache.
closed
17 Volume modes Total number of volumes in each caching
state. Note that the initial release of XFC
only supports VIOC compatible mode. Future
releases will support full mode.
18 I/O Statistics Systemwide distribution of I/O sizes
(rounded up).
19 MAX_IO_SIZE Current setting of the system parameter VCC_
MAX_IO_SIZE in blocks. The extended file
cache (XFC) will only cache files up to this
size.
20 Reads Number of reads for the entire system.
21 Read Hits Number of reads satisfied from the cache.
22 Writes Number of writes for the entire system.
3.$ SHOW MEMORY/CACHE=(VOLUME=*)
System Memory Resources on 20-JAN-2001 15:35:32.51
Extended File Cache Volume Statistics:
_$7$DKA200: (DISK$X6XV_BRAHMA), Caching mode is VIOC Compatible
Open files 1 372 Closed files 9 395
Files ever opened 2 1007 Files ever deposed 10 240
Allocated pages 3 6405 Locks acquired 11 736
Total QIOs 4 166552 Read hits 12 115984
Virtual reads 5 120068 Virtual writes 13 46484
Hit rate 6 69 % Read aheads 14 11766
Read throughs 7 120021 Write throughs 15 46484
Read arounds 8 47 Write arounds 16 0
Ave Disk I/O Resp Time incl cache hits (microseconds)17 3497
Total of 1 volumes in cache
Extended File Cache Usage
Shows the use of the Extended File Cache facility on an Alpha
system.
1 Open files Number of files that are currently open and
cached by the extended file cache on this volume
at the instant the SHOW command was issued.
2 Files ever Number of times the extended file cache has been
opened requested to open a file on this volume.
3 Allocated Number of main memory data pages currently
pages being used by the extended file cache to contain
actual file data, for this volume.
4 Total QIOs Total number of QIO and PAGE I/O calls received
by the extended file cache on this volume.
5 Virtual Cumulative number of Virtual Read requests
reads received by the extended file cache on this
volume.
6 Hit rate Percentage of Total QIOs that were completed
by copying data from cache, rather than issuing
real I/O to a volume.
7 Read Number of Virtual Reads that are capable of
throughs being satisfied by the extended file cache.
8 Read Number of Virtual Reads that cannot be satisfied
arounds by the extended file cache. Reasons for this
include the presence of a non-XFC compliant node
in an OpenVMS cluster, and the receipt of an I/O
that is larger than VCC_MAX_IO_SIZE.
9 Closed Number of closed files the extended file cache
files has in memory. If a subsequent file access
occurs, data will be accessible from main memory
rather than having to issue I/O to the real
volume.
10 Files Files removed from memory. Reasons the extended
ever deposed file cache may remove a file from its memory
include requests for memory from the rest of
the system, and conflicting access modes in a
cluster.
11 Locks Current number of file access locks that are in
acquired use on this volume.
12 Read hits Cumulative number of times a read has been
satisfied from the data cache.
13 Virtual Cumulative number of virtual write I/Os received
writes on this volume by the cache.
14 Read Cumulative number of times the extended file
aheads cache issued read ahead I/Os on this volume
after detecting sequential file I/O virtual
reads.
15 Write Cumulative number of times a virtual write has
throughs been capable of modifying cached data.
16 Write Cumulative number of times a virtual write has
arounds been detected that cannot update data in cache
memory.
17 Average Average disk I/O response time, including cache
Disk I/O hits, in microseconds. Note that on a symmetric
Response multiprocessing (SMP) system, the response time
Time only includes that of I/Os starting or finishing
on the same CPU. Any physical I/Os are ignored.
4.$ SHOW MEMORY/CACHE=(VOL=DKA100,TOPQIO=3)
System Memory Resources on 3-NOV-2001 18:36:12.79
Extended File Cache Top QIO File Statistics:
_$7$DKA200: (DISK$X6Y0_RESD), Caching mode is VIOC Compatible
_$7$DKA200:[SYS0.SYSEXE]SYSDUMP.DMP;2 (open)
Caching is enabled, active caching mode is Write Through
Allocated pages 1 334 Total QIOs 6 1712
Read hits 2 1559 Virtual reads 7 1712
Virtual writes 3 0 Hit rate 8 91 %
Read aheads 4 0 Read throughs 9 0
Write throughs 5 0 Read arounds 10 0
Write arounds 11 0
_$7$DKA200:[VMS$COMMON.SYSEXE]SYS$QUEUE_MANAGER.QMAN$JOURNAL;1 (open)
Caching is enabled, active caching mode is Write Through
Allocated pages 931 Total QIOs 1057
Read hits 5 Virtual reads 1044
Virtual writes 13 Hit rate 0 %
Read aheads 2 Read throughs 1044
Write throughs 13 Read arounds 0
Write arounds 0
_$7$DKA200:[VMS$COMMON.SYSLIB]DECC$SHR.EXE;1 (open)
Caching is enabled, active caching mode is Write Through
Allocated pages 135 Total QIOs 730
Read hits 673 Virtual reads 730
Virtual writes 0 Hit rate 0 %
Read aheads 2 Read throughs 0
Write throughs 0 Read arounds 0
Write arounds 0
Total of 3 files for this volume
Extended File Cache Top QIO File Statistics Usage
Shows the use of the Extended File Cache Top QIO File
Statistics facility on an Alpha system.
1 Allocated pages Number of main memory data pages currently
being used by the extended file cache to
contain actual file data, for this volume
2 Read hits Cumulative number of times a read has been
satisfied from the data cache.
3 Virtual writes Cumulative number of virtual write I/Os
received on this volume by the cache.
4 Read aheads Cumulative number of times the extended file
cache issued read ahead I/Os on this volume
after detecting sequential file I/O virtual
reads.
5 Write throughs Cumulative number of times a virtual write
has been capable of modifying cached data.
6 Total QIOs Total number of QIO and PAGE I/O calls
received by the extended file cache on this
volume.
7 Virtual reads Cumulative number of Virtual Read requests
received by the extended file cache on this
volume.
8 Hit rate Percentage of Total QIOs that were completed
by copying data from cache, rather than
issuing real I/O to a volume.
9 Read throughs Number of Virtual Reads that are capable of
being satisfied by the extended file cache.
10 Read arounds Number of Virtual Reads that cannot be
satisfied by the extended file cache.
Reasons for this include the presence of
a non-XFC compliant node in an OpenVMS
cluster, and the receipt of an I/O that
is larger than VCC_MAX_IO_SIZE.
11 Write arounds Cumulative number of times a virtual write
has been detected that cannot update data in
cache memory.
5.$ SHOW MEMORY/CACHE=(VOL=DKA100,TOPHITRATE=3)
System Memory Resources on 3-NOV-2001 18:36:12.79
Extended File Cache Top Hitrate File Statistics:
_$7$DKA200: (DISK$X6Y0_RESD), Caching mode is VIOC Compatible
_$7$DKA200:[VMS$COMMON.SYSLIB]SMGSHR.EXE;1 (open)
Caching is enabled, active caching mode is Write Through
Allocated pages 1 16 Total QIOs 6 277
Read hits 2 267 Virtual reads 7 277
Virtual writes 3 0 Hit rate 8 96 %
Read aheads 4 0 Read throughs 9 277
Write throughs 5 0 Read arounds 10 0
Write arounds 11 0
_$7$DKA200:[VMS$COMMON.SYSLIB]UTIL$SHARE.EXE;1 (open)
Caching is enabled, active caching mode is Write Through
Allocated pages 8 Total QIOs 185
Read hits 178 Virtual reads 185
Virtual writes 0 Hit rate 96 %
Read aheads 1 Read throughs 185
Write throughs 0 Read arounds 0
Write arounds 0
_$7$DKA200:[VMS$COMMON.SYSLIB]CMA$TIS_SHR.EXE;1 (open)
Caching is enabled, active caching mode is Write Through
Allocated pages 6 Total QIOs 165
Read hits 159 Virtual reads 165
Virtual writes 0 Hit rate 96 %
Read aheads 2 Read throughs 165
Write throughs 0 Read arounds 0
Write arounds 0
Total of 3 files for this volume
Extended File Cache Top Hitrate File Statistics Usage
Shows the use of the Extended File Cache Top Hitrate File
Statistics facility on an Alpha system.
1 Allocated pages .Number of main memory data pages currently
being used by the extended file cache to
contain actual file data, for this volume
2 Read hits Cumulative number of times a read has been
satisfied from the data cache.
3 Virtual writes Cumulative number of virtual write I/Os
received on this volume by the cache.
4 Read aheads Cumulative number of times the extended file
cache issued read ahead I/Os on this volume
after detecting sequential file I/O virtual
reads.
5 Write throughs Cumulative number of times a virtual write
has been capable of modifying cached data.
6 Total QIOs Total number of QIO and PAGE I/O calls
received by the extended file cache on this
volume.
7 Virtual reads Cumulative number of Virtual Read requests
received by the extended file cache on this
volume.
8 Hit rate Percentage of Total QIOs that were completed
by copying data from cache, rather than
issuing real I/O to a volume.
9 Read throughs Number of Virtual Reads that are capable of
being satisfied by the extended file cache.
10 Read arounds Number of Virtual Reads that cannot be
satisfied by the extended file cache.
Reasons for this include the presence of
a non-XFC compliant node in an OpenVMS
cluster, and the receipt of an I/O that
is larger than VCC_MAX_IO_SIZE.
11 Write arounds Cumulative number of times a virtual write
has been detected that cannot update data in
cache memory.
6.$ SHOW MEMORY/CACHE=(FILE=SYS$LOGIN:*.*,OPEN,CLOSED)
System Memory Resources on 3-NOV-2001 18:36:12.79
Extended File Cache Statistics:
_$7$DKA200:[SYS0.SYSMGR]ACCOUNTNG.DAT;1 (open)
Caching is enabled, active caching mode is Write Through
Allocated pages 1 1 Total QIOs 6 17
Read hits 2 0 Virtual reads 7 1
Virtual writes 3 16 Hit rate 8 0 %
Read aheads 4 0 Read throughs 9 0
Write throughs 5 16 Read arounds 10 0
Write arounds 11 0
_$7$DKA200:[SYS0.SYSMGR]ACME$SERVER.LOG;129 (open)
Caching is enabled, active caching mode is Write Through
Allocated pages 1 Total QIOs 2
Read hits 0 Virtual reads 1
Virtual writes 1 Hit rate 0 %
Read aheads 0 Read throughs 1
Write throughs 1 Read arounds 0
Write arounds 0
_$7$DKA200:[SYS0.SYSMGR]CLUE$STARTUP_BRAHMA.LOG;935 (closed)
Caching is enabled, active caching mode is Write Through
Allocated pages 2 Total QIOs 32
Read hits 0 Virtual reads 0
Virtual writes 32 Hit rate 0 %
Read aheads 0 Read throughs 0
Write throughs 32 Read arounds 0
Write arounds 0
.
.
.
_$7$DKA200:[VMS$COMMON.SYSMGR]VMS$AUDIT_SERVER.DAT;1 (open)
Caching is enabled, active caching mode is Write Through
Allocated pages 1 Total QIOs 8
Read hits 3 Virtual reads 8
Virtual writes 0 Hit rate 37 %
Read aheads 1 Read throughs 8
Write throughs 0 Read arounds 0
Write arounds 0
Total of 50 files for this volume
Extended File Cache Statistics Usage
Shows the use of the Extended File Cache Statistics facility on
an Alpha system.
1 Allocated pages .Number of main memory data pages currently
being used by the extended file cache to
contain actual file data, for this volume
2 Read hits Cumulative number of times a read has been
satisfied from the data cache.
3 Virtual writes Cumulative number of virtual write I/Os
received on this volume by the cache.
4 Read aheads Cumulative number of times the extended file
cache issued read ahead I/Os on this volume
after detecting sequential file I/O virtual
reads.
5 Write throughs Cumulative number of times a virtual write
has been capable of modifying cached data.
6 Total QIOs Total number of QIO and PAGE I/O calls
received by the extended file cache on this
volume.
7 Virtual reads Cumulative number of Virtual Read requests
received by the extended file cache on this
volume.
8 Hit rate Percentage of Total QIOs that were completed
by copying data from cache, rather than
issuing real I/O to a volume.
9 Read throughs Number of Virtual Reads that are capable of
being satisfied by the extended file cache.
10 Read arounds Number of Virtual Reads that cannot be
satisfied by the extended file cache.
Reasons for this include the presence of
a non-XFC compliant node in an OpenVMS
cluster, and the receipt of an I/O that
is larger than VCC_MAX_IO_SIZE.
11 Write arounds Cumulative number of times a virtual write
has been detected that cannot update data in
cache memory.
7.$ SHOW MEMORY/PHYSICAL_PAGES
System Memory Resources on 3-NOV-2001 16:11:30.76
Physical Memory Usage (pages): Total 1 Free 2 In Use 3 Modified 4
Main Memory (32.00Mb) 65536 44233 20955 308
Of the physical pages in use, 10970 pages are permanently allocated
to VMS.
Physical Memory Usage
Shows the use of physical memory.
1 Total Number of physical memory pages available for
general system use. Multiport memory pages used
for shared memory global sections, mailboxes,
and common event blocks are not included in this
number.
2 Free Number of pages on the free page list.
3 In Use Number of pages currently being used. This number
is calculated by adding the number of pages on the
free, modified, and bad lists and then subtracting
that sum from the total number of available pages.
4 Modified Number of pages on the modified page list.
Bad Page List
Shows the contents of the bad page list.
NOTE
This display is written only when there are pages on the bad
page list.
Total Number of pages on the bad page list.
Dynamic Number of memory errors detected after the system
was booted.
I/O Errors Number of errors detected during page fault
handling.
Static Number of memory errors detected during boot-time
scan.
By default, either single-bit or double-bit errors cause the
pages to be removed during the boot-time scan.
Pages Allocated to OpenVMS
Any SHOW MEMORY display that includes the physical memory
display concludes with the number of pages permanently
allocated to the OpenVMS system. These pages include nonpaged
executive code and data, the PFN database, nonpaged dynamic
memory, the interrupt stack, and the system page table.
8. $ SHOW MEMORY/SLOTS
System Memory Resources on 3-NOV-2001 16:11:35.31
Slot Usage (slots): Total 1 Free 2 Resident 3 Swapped 4
Process Entry Slots 75 28 46 1
Balance Set Slots 70 26 44 0
Slot Usage (slots)
Displays the use of process entry slots and balance set slots.
1 Total Number of process entry slots (the value of the
system parameter MAXPROCESSCNT) and balance
set slots (the value of the system parameter
BALSETCNT) permanently allocated when the system
was bootstrapped.
2 Free Number of slots currently available.
3 Resident Number of slots currently used by memory-resident
processes. The number of balance set slots in use
can never be any larger than the number of process
entry slots in use because the SWAPPER and NULL
processes have process entry slots but do not
require balance set slots.
4 Swapped Number of slots used by outswapped processes.
For process entry slots, this number includes all
processes that have been partially outswapped. For
balance set slots, this number includes those
processes that have had their process bodies
outswapped but have process headers that are still
resident.
9. $ SHOW MEMORY/POOL
System Memory Resources on 5-DEC-2001 03:59:35.29
Dynamic Memory Usage (bytes): Total 1 Free 2 In Use 3 Largest 4
Nonpaged Dynamic Memory 24993792 23511872 1481920 23363776
Bus Addressable Memory 131072 114688 16384 114688
Paged Dynamic Memory 5799936 3530784 2269152 3530176
Lock Manager Dynamic Memory 1048576 254976 793600
Dynamic Memory Usage (in bytes)
Shows the use of the nonpaged and paged pool areas that
allocate variably sized blocks.
1 Total Total number of bytes set aside for each area.
2 Free Total amount of free space in each dynamic memory
area.
3 In Use Amount of space currently allocated from each
area. This number is the total size minus the
number of free bytes.
4 Largest Size of the largest contiguous block in each area.
For the paged pool, this number represents the
largest block that can be allocated. For the
nonpaged pool, an allocation request larger
than this number will cause the nonpaged pool
to grow (if other constraints allow growth). This
attribute does not apply to the lock manager, as
all items for the lock manager are the same size.
10. $ SHOW MEMORY/POOL/FULL
System Memory Resources on 5-DEC-2001 03:59:35.29
Nonpaged Dynamic Memory (Lists + Variable)
Current Size (bytes) 1 24993792 Current Size (pagelets) 1 48816
Initial Size (NPAGEDYN) 2 24993792 Initial Size (pagelets) 2 48816
Maximum Size (NPAGEVIR) 3499998720 Maximum Size (pagelets) 3 976560
Free Space (bytes) 4 22230144 Space in Use (bytes) 52763648
Largest Variable Block 6 19676672 Smallest Variable Block 7 2176
Number of Free Blocks 8 38334 Free Blocks LEQU 64 Bytes9 0
Free Blocks on Lookasides16 38330 Lookaside Space (bytes) 2537472
Bus Addressable Memory (Lists + Variable)
Current Size (bytes) 1 131072 Current Size (pagelets) 1 256
Initial Size (NPAGEDYN) 2 131072 Initial Size (pagelets) 2 256
Free Space (bytes) 4 114688 Space in Use (bytes) 5 16384
Largest Variable Block 6 114688 Smallest Variable Block 7 114688
Number of Free Blocks 8 1 Free Blocks LEQU 64 Bytes9 0
Free Blocks on Lookasides16 0 Lookaside Space (bytes) 0
Paged Dynamic Memory (Lists + Variable)
Current Size (MB) 1 22.88 Current Size (pagelets) 1 46864
Free Space (MB) 4 21.96 Space in Use (MB) 5 0.91
Largest Variable Block 6 21.77 Smallest Variable Block(MB)721.77
Number of Free Blocks 8 166 Free Blocks LEQU 64 Bytes 9 4
Free Blocks on Lookasides16 165 Lookaside Space (KB) 201.85
Over-limit Lookaside Blocks17 3 Over-limit Space (KB) 7.45
Lock Manager Dynamic Memory
Current Size (Mbytes) 1 13.85 Current Size (pages) 1 1774
Free Space (Mbytes) 4 10.06 Hits 12 54050
Space In Use 5 3.79 Misses 13 1664
Number of Empty Pages 10 26 Expansions 14 1792
Number of Free Packets 11 41244 Packet Size 15 256
Dynamic Memory
Shows the use of dynamic memory areas consisting of variably
sized blocks.
1 Current Size Current size (in 512-byte pagelets on Alpha
) of each dynamic memory area. For the lock
manager display, the unit of measurement is
megabytes.
2 Initial Size Initial size of nonpaged dynamic memory and
the name of the system parameter (NPAGEDYN)
that controls this size.
3 Maximum Size Maximum size to which nonpaged dynamic
memory can grow and the name of the system
parameter (NPAGEVIR) that controls this
size.
4 Free Space Amount of free space in each dynamic memory
area.
5 Space in Use Amount of space currently allocated from
each area.
6 Largest Block Size of the largest contiguous area in each
pool area.
7 Smallest Block Size of the smallest hole (free block) in
each pool area.
8 Free Blocks Total number of free blocks in each pool
area. The size of this number is a measure
of pool fragmentation.
9 Blocks LEQU 64 Number of free blocks that are 64 bytes
long or shorter. This number is another
measure of pool fragmentation because
while allocation of these small blocks is
unlikely, they contribute to the allocation
time whenever an allocation request is made.
10 Empty Pages Number of pages that do not have any packets
allocated.
11 Free Packets Total number of packets not in use. This
number is the sum of free packets from
partially used pages and the packets of
all Empty Pages.
12 Hits Total number of packet allocations.
13 Misses Total number of packet allocation requests
that could not be satisfied because the
number of packets requested were not
available. A miss causes dynamic memory
to expand by one page to satisfy the packet
allocation request.
14 Expansions Total number of times that dynamic memory
increased by a page to satisfy packet
allocation requests.
15 Packet Size Packet size of 256 bytes, which is used by
the lock manager to hold either a lock block
data structure or a resource block data
structure.
16 Lookasides Total number of memory packets placed
Free Blocks on "lookaside lists". If a packet of the
correct size is on a lookaside list, it can
be allocated very quickly and efficiently,
however, it cannot then be used as part of
any other size packet. An excess of packets
on the lookaside list can be a cause for the
inability to allocate other sizes.
17 Over-limit Total number of memory packets that exist
Lookaside Blocks on "lookaside lists" that are no longer
actively used because the SYSGEN parameter
PAGED_LAL_SIZE was lowered. These packets
will be available for use again if the
SYSGEN parameter is increased to include
them, or if there was a paged pool shortage
and they are reclaimed. If there are no
lookaside list packets on these "over-limit"
lists then this line will not appear.
11. $ SHOW MEMORY/FILES
System Memory Resources on 22-MAY-2001 19:04:19.67
Swap File Usage (8KB pages): Index 1 Free Size
DISK$ALPHASYS:[SYS48.SYSEXE]SWAPFILE.SYS 1 904 904
DISK$SWAP:[SYS48.SYSEXE]SWAPFILE.SYS;1 2 1048 1048
Total size of all swap files: 1952
Paging File Usage (8KB pages): Index 2 Free Size
DISK$PAGE:[SYS48.SYSEXE]PAGEFILE.SYS;1 253 16888 16888
DISK$ALPHASYS:[SYS48.SYSEXE]PAGEFILE.SYS 254 16888 16888
Total size of all paging files: 33776
Total committed paging file usage: 3 1964
Paging File Usage (in blocks)
Shows the usage of paging and swapping files.
1 Swap File Usage Number of swap files. Begins with an index
value of 1 and increases in count.
2 Paging File Number of page files. Begins with an index
Usage value of 254 and decreases in count.
3 Total Paging Total committed page file usage. As in
File Usage previous releases, more pages can reside
in page-file sections systemwide than would
fit into installed page files.