Advanced Topics › How You Control the Response of TPCF During Allocation Recovery › Responding When a Job is Waiting for a Device

Responding When a Job is Waiting for a Device

z/OS issues message IEF433D whenever you (or TPCF) tell z/OS to make a job wait for a device to become available. You can tell TPCF how to respond to the z/OS IEF433D message by specifying one of these values for the SETOPTION AUTOREPLY=(IEF433D=value) command:

• If you specify IEF433D=HOLD, then waiting jobs receive a suitable device before other jobs. However, z/OS still allows jobs using dynamic allocation to allocate a device. When HOLD is replied, the job continues to hold device group locks, preventing other jobs requesting the locks from proceeding in allocation.

  Important! Do not specify IEF433D=HOLD if you are reserving devices for jobs through the VARY command, if you have defined elimination logic in the TPCEDLXT exit routine, or if you are running with tape robotic software. Replying HOLD under these circumstances can cause jobs to fail during allocation. We recommend that you do not specify IEF433D=HOLD, even when you are not reserving devices or using an exit routine, since allocation processing may be slowed down. A reply of HOLD results in the job holding allocation resources that may be needed by other jobs.

• If you specify IEF433D=NOHOLD, then jobs are placed on a wait queue until a device of the correct type deallocates or a VARY AVAILABLE command is issued for an eligible device. When NOHOLD is replied, the device group locks are released.
• If you specify IEF433D=MANUAL, then you can make a choice between HOLD and NOHOLD whenever the message is issued. If you specify IEF433D=MANUAL, then you must also specify IEF238D=MANUAL.