DFS868I (INPUT|OUTPUT) VOLUMES: volser1, volser2, etc..
Explanation
This message is issued one or more times to display the volume serial identifiers of the volumes used to contain the INPUT/OUTPUT work data set of the issuing program.
Problem determination
2, 3, 8, 36. Also, if running under the Utility Control Facility, rerun the job with a FUNCTION=OP,MSGNUM=868 control statement in the DFSYSIN data set. Supply a SYSUDUMP DD statement to this step.