Failure to Reach a Restricted State

We recently had a full backup fail because the system did not reach a restricted state and the RSU IPL'd the system. We suspected that the problem was a subsystem did not end, but the problem became, which subsystem was it. Help Systems gave us the clue that there would be a message in QHST that would state the name of the subsystem that was active when the system IPL'D. I did find that message. I found you can search QHST for the specific message ID of CFP0918 to find that message easly. This worked on V5R4M5, but I cannot say if will work on others. Here is the command:

DSPLOG PERIOD((*AVAIL 062108)) MSGID(CPF0918)