Controlling the IRLM
The internal resource lock manager (IRLM) subsystem manages Db2 locks.
About this task
The particular IRLM to which Db2 is connected is specified in the Db2 load module for subsystem parameters. The particular IRLM is also identified as a z/OS subsystem in the SYS1.PARMLIB member IEFSSNxx. That name is used as the IRLM procedure name (irlmproc) in z/OS commands.
Each IMS and Db2 subsystem must use a separate instance of IRLM.
In a data sharing environment, the IRLM handles global locking, and each Db2 member has its own corresponding IRLM.
Procedure
To
control the IRLM:
Issue the appropriate z/OS command
for the action that you want to take.
In each command description, irlmproc is the IRLM procedure name and irlmnm is the IRLM subsystem name.
MODIFY irlmproc,ABEND,DUMP- Abnormally terminates the IRLM and generates a dump.
MODIFY irlmproc,ABEND,NODUMP- Abnormally terminates the IRLM but does not generate a dump.
MODIFY irlmproc,DIAG- Initiates diagnostic dumps for IRLM subsystems in a data sharing group when a delay occurs.
MODIFY irlmproc,SET- Dynamically sets the maximum amount of private virtual (PVT) storage or the number of trace buffers that are used for this IRLM.
MODIFY irlmproc,STATUS- Displays the status for the subsystems on this IRLM.
START irlmproc- Starts the IRLM.
STOP irlmproc- Stops the IRLM normally.
TRACE CT,OFF,COMP=irlmnm- Stops IRLM tracing.
TRACE CT,ON,COMP=irlmnm- Starts IRLM tracing for all subtypes (DBM, SLM, XIT, and XCF).
TRACE CT,ON,COMP=irlmnm,SUB=(subname)- Starts IRLM tracing for a single subtype.
