Another one of Kershaw Mehta's presentations on the care and feeding of OS/390 Unix Services. This session talked in gross terms about how to apply service to the Unix HFS.
There are any number of gotchas. Although the HFS is logically part of your SYSRES, the root file system cannot actually reside on your SYSRES because the HFS must be system managed. And you cannot have an SMS-managed SYSRES.
He ran through three separate scenarios on how IBM recommends that you apply maintenance, depending on your situation. The details are far too wide-ranging and mind-numbing to list here. And I'm not at all sure which are most important to summarize anyway; our own maintenance mechanism is wayyyy up in the air right now.