SSM SHUTSYS application automates z/OS system shutdown. It is part of the aggressive system shutdown sample procedures, as described within the SHUTSYS1 OPS/REXX program sample, that contains initial procedures to perform a system shutdown and that is called via the SHUTSYS and SHUTMAINT option, initiated from the sample SSMCNTL AOF rule.
- Entering the pseudo command 'SSM SHUTSYS' will cause the SSMCNTL sample rule to trigger this SHUTSYS1 OPS/REXX program and initiate an attempt to begin a complete system shutdown.
- Entering the the pseudo command 'SSM SHUTMAINT' will cause the SSMCNTL sample rule to trigger this SHUTSYS1.
The Schedule Manager enables you to schedule times when the System State Manager feature changes the states of system resources.
If both features are implemented and the default SHUTSYS1 OPS/REXX sample we provide in CCLXSAMP is used, it can happen that they could generate a conflict at Z/OS Shutdown time due to a very timing dependent course of actions.
In fact if the SSM SHUTSYS command is issued that will start the Z/OS Shutdown, and at the same time a new period in the actual schedule starts in the Schedule Manager, the SSM (re-)starts every resource.
This will cause a failure in the SSM SHUTSYS procedure that stops the unattended Z/OS System Shutdown.
In order to be sure the SSM SHUTSYS command can be always issued, avoiding any conflict with the Schedule Manager definitions done, it is important to include a command in the SHUTSYS1 REXX program to disable the Schedule Manager dynamic TOD rule, just before initiate the shutdown procedure.
This can be done with the statements below:
In this way the Schedule Manager will not attempt to activate the resources and the shutdown procedure can progress correctly.