In a clustered environment, the RMU Show Locks command displays
detailed lock information for your current node and may display
information about known remote locks.
The RMU Show Locks command displays information about process
locks for all active databases on a specific node. A process
requesting a lock can have one of three states: owning, blocking,
or waiting. A process is considered to be owning when the lock
request is granted. A process is considered to be blocking when
the lock request is granted and its mode is incompatible with
other waiting locks. A process is considered to be waiting when
it is prevented from being granted a lock due to the presence
of other granted locks whose modes are incompatible with the
process' requested mode.
Using the RMU/SHOW LOCKS command can be difficult on systems
with multiple open databases due to the amount of output and
difficulty in determining what database a particular lock
references. The RMU/SHOW LOCKS command, when supplied with a
root file specification, can be used to additionally filter
lock displays to a specific database. Note that in some cases
the RMU/SHOW LOCKS command may be unable to filter locks prior
to display. And when using the database "LOCK PARTITIONING IS
ENABLED" feature for a database, the RMU/SHOW LOCKS command with
a root file specification will be unable to associate area, page,
and record locks with the specified database because the database
lock is not the lock tree root for these lock types.
The values for the Mode qualifier: Blocking and Waiting, can be
combined with the Process and Lock qualifiers to indicate which
of the following types of information is displayed:
o If the Blocking option is specified, information is displayed
about processes whose locks are blocking other processes'
locks.
o If the Waiting option is specified, information is displayed
about processes whose locks are waiting for other processes'
locks.
o If the Process qualifier is specified, information is
displayed for a specified list of processes.
o If the Lock qualifier is specified, information is displayed
for a specified list of locks. When no qualifiers are
specified, a list of all active locks in the OpenVMS locks
database is displayed.
Use the qualifiers individually or in combination to display the
required output. See Lock Qualifier Combinations for all possible
qualifier combinations and the types of output they produce.
If you do not specify any qualifiers, a complete list of locks
is displayed. The volume of information from this report can
be quite large. Therefore, you should use the Output qualifier
to direct output to a file, instead of allowing the output
to display to SYS$OUTPUT. Each output contains a heading that
indicates what qualifiers, if any, were used to generate the
output.
Table 16 Lock Qualifier Combinations
Mode Option
Object Argument Argument Output
Process Locks for the specified
processes
Process Blocking Processes blocking the
specified processes
Process Waiting Processes waiting for the
specified processes
Process All Process locks for the
specified processes
Process Full Special process locks for
the specified processes
Process Blocking, Processes blocking and
Waiting waiting for the specified
processes
Process Blocking Full Special process locks
blocking the specified
processes
Process Waiting Full Special process locks
waiting for the specified
processes
Process Blocking, Full Special process locks
Waiting blocking and waiting for
the specified processes
Process All, Full Process and special
process locks for the
specified processes
Lock Locks for the specified
locks
Lock Blocking Processes blocking the
specified locks
Lock Waiting Processes waiting for the
specified locks
Lock Full Special process locks for
the specified locks
Lock Blocking Full Special process locks
blocking the specified
locks
Lock Waiting Full Special process locks
waiting for the specified
locks
Lock Blocking, Processes blocking and
Waiting waiting for the specified
locks
Lock Blocking, Full Special process locks
Waiting blocking and waiting for
the specified locks
Blocking Lock requests that are
blocked
Waiting Lock requests that are
waiting
Blocking, Lock requests that are
Waiting blocking and waiting
Process Locks for specified
Lock processes and locks
Process Blocking Processes blocking the
Lock specified processes and
locks
Process Waiting Processes waiting for the
Lock specified processes and
locks
Process Blocking, Processes blocking and
Lock Waiting waiting for the specified
processes and locks
Process Blocking Full Special process locks
Lock blocking the specified
processes and locks
Process Waiting Full Special process locks
Lock waiting for the specified
processes and locks
Process All Process locks for the
Lock specified processes and
locks
Process Full Special process locks for
Lock the specified processes
and locks
Process Blocking Full Special process locks
Lock blocking the specified
processes and locks
Process All, Full Process and special
Lock process locks for the
specified processes and
locks
You can display only those processes that you have privilege to
access. Furthermore, certain special database processes are not
displayed, unless you specifically indicate that all processes
are to be displayed. The report heading indicates what qualifiers
were used to generate the output.