I did find a case in which I had difficulty getting a TSM library client to do e.g. reclamation when I had mount retention set "wrong":
If you've got a library client which you've set to have access to two drives, and mount retention set to some normal value on the library manager (say, 5 minutes) you can enter a state in which a reclamation process does: - Mount source volume - Mount destination volume [ copy data, finish with dest. ] - Make mount request for new volume - Get refused: too many mount points - Process fails, TSM admin gets irritated. What I eventually did was set the library manager to have zero mount retention, which fixed this. My drives stay busy, with a line queueing up, most of the day. So I didn't mind the more-or-less immediate dismount. - Allen S. Rout
