The checkpoint restart function deletes members that were added after the checkpoint. Because this action may delete members written by another job (another job may have been executed between the original and restart executions of the subject job), restart at a checkpoint should not be requested.

If a PDS is open for output at checkpoint time, any new members added later will be deleted during a restart from this checkpoint. No members will be deleted when a PDS is open for update. Be cautious when restarting from checkpoints having PDSs open for update.

Caution: When a program copies a PDS, the members in the copy generally reside in different locations within the data set. If you take a checkpoint while a PDS is open and then copy members, perhaps with IEBCOPY or DFSMSdss^™, you cannot do a deferred checkpoint restart.