The checkpoint at end-of-volume provides an external checkpoint function with no user program modifications. It is executed immediately prior to the invocation of any checkpoint in a user EOV exit routine. Redundancy occurs if a user exit routine is supplied and checkpoint at end-of-volume is invoked for the same data set's end-of-volume occurrence.

Checkpoint at end-of-volume is executable only if the CHKPT=EOV parameter is specified for multivolume data sets or for the second, third, etc., data sets of a sequential concatenation. If the first data set of a concatenation is a multivolume data set, this parameter is also valid on that DD statement.

Checkpoint at end-of-volume issues a CHKPT macro. If, at EOV, a return code of 08 is presented, the CHKPT macro is executed again. Return code 08 indicates that end-of-extent or end-of-volume occurred for the SYSCKEOV DD before completion of the checkpoint entry. The retry of return code 08 uses secondary space, if provided.

This message is preceded by a checkpoint/restart error message (prefixed "IHJ") that describes the nature of the problem. For more details about these error messages see z/OS MVS System Messages, Vol 1 (ABA-AOM), z/OS MVS System Messages, Vol 2 (ARC-ASA), z/OS MVS System Messages, Vol 3 (ASB-BPX), z/OS MVS System Messages, Vol 4 (CBD-DMO), z/OS MVS System Messages, Vol 5 (EDG-GFS), z/OS MVS System Messages, Vol 6 (GOS-IEA), z/OS MVS System Messages, Vol 7 (IEB-IEE), z/OS MVS System Messages, Vol 8 (IEF-IGD), z/OS MVS System Messages, Vol 9 (IGF-IWM), and z/OS MVS System Messages, Vol 10 (IXC-IZP).

In any event, processing continues, and this message is generated for each unsuccessful invocation of the checkpoint at end-of-volume until step termination occurs. Operator intervention is required to halt further processing prior to step end.