Advanced Topics › Product Termination Considerations › How You Quiesce and Restart CA MIM

How You Quiesce and Restart CA MIM

When you need to temporarily deactivate CA MIM (for example, while you perform maintenance on a system), use the CA MIM QUIESCE command. Then, use the RESTART command to reactivate CA MIM.

Important! Quiesce CA MIM only when you are bringing z/OS down on that system.

To quiesce CA MIM and z/OS

1. Issue the QUIESCE command.

   CA MIM performs quiesce processing and then goes into a “wait state.” This means that it will not try to access its control file from that system.

   Important! Begin the QUIESCE command with the CA MIM command prefix character or a z/OS MODIFY command. Otherwise, you will quiesce z/OS. If you are concerned about errors, then use the CA MIM DISABLE command to disable the QUIESCE command.

   CA MIM issues the following messages as it quiesces:

   MIM0280I System sysid QUIESCE pending
   MIM0282I CA‑Multi-image Manager system sysid is QUIESCED
   

   Other systems display MIM0061 messages because the quiesced system has stopped updating its time stamp in the control file. Do not respond to these messages. Eventually, these systems display MIM0063 messages to tell you that the quiesced system seems to be “asleep.” Do not issue the FREE command for the quiesced system. Otherwise, CA MIM issues a U0322 abend code and MIM0112 message when you restart the quiesced system.

2. Quiesce z/OS and perform any required tasks while your system is down.
3. Reactivate your hardware to restart z/OS.
4. Issue a RESTART command.

   This restarts CA MIM on your quiesced system. CA MIM removes highlighting for the MIM0282I messages and reactivates itself. When systems have synchronized and the restart is complete, the following message is issued:

   MIM0281I  system sysid RESTART complete
   

MIMMVS--WAITSTATE and SHUTDOWN WAIT

To preserve data integrity, there are situations where you may need to shut down CA MIM in a disabled wait state. Two parameters have been added to CA MIM to control and define how CA MIM enters a disabled wait state:

• The MIMINIT WAITSTATE statement defines the conditions under which CA MIM will enter a disabled Wait state. You can also set the value for this keyword in the PARM field in the CA MIM startup JCL PROC sample.

  Important: Use this parameter with careful consideration. Specifying any value other than NEVER (default) puts CA MIM into a disabled state that abrubtly halts the entire system. Under some circumstances, this is a good choice, because it is the only way to ensure the integrity of shared data.

  You should choose a value other than NEVER only when GDIF is activated. All other CA MIM components (TPCF, GTAF, EDIF, ECMF, and ICMF) can all be stopped safely, and do not require the wait state to ensure data integrity.

  Note: The SETOPTION SHUTDOWN command will NOT be honored when WAITSTATE is set to anything other than NEVER.

• The SHUTDOWN WAIT command sets the status of the local system to a freed state, then puts the system into a disabled wait state.

For more information about these keywords, see the Statement and Command Reference Guide.