Using checkpoint/restart

When issuing checkpoints and then restarting a task, the restarted task must request control of all resources required to continue processing. Resources are not automatically returned to the task upon restart.

You can use the checkpoint/restart facility with the following restrictions:

A routine that is restricted from issuing SVCs is also restricted from establishing checkpoints because programmer-designated checkpoints require the use of the checkpoint SVC.
An exit routine other than the end-of-volume exit routine cannot request a checkpoint.
A routine invoked by a program call (PC) cannot request checkpoints because the system environment might be different at the time of the restart from what it was at the time of the checkpoint. This could lead to unpredictable results on the return linkage (PT).
A routine with a PCLINK STACK request outstanding cannot establish a checkpoint.
Subsystems that use the TCB subsystem affinity service cannot issue checkpoints.
A program that has selected a data in virtual object using the IDENTIFY service cannot request a checkpoint until it invokes the corresponding UNIDENTIFY service.

For additional information concerning the restrictions and use of the checkpoint/restart facility see z/OS DFSMSdfp Checkpoint/Restart.