I have a DPM 2012 server (but I've heard the same behaviour happens with DPM 2010) I'm using to backup my environment; it's connected to a single tape drive (no library), so tape rotation is manual.
My backup schedule is:
- Disk backups everyday at 20:00
- Tape backups everyday at 23:00
- Tape retention 1 week
When I inspect a tape after a successful backup, DPM correctly say all recovery points on the tape are going to expire at backup day + 7 days, at (about) 20:00.
The problem is, after 7 days, when that tape is put back into the drive, DPM complains about not having a free tape to use. At 23:00, when it starts the new tape backups. When the old ones on that tape should already have expired three hours before.
The tape backups can instead be completed successfully on the same tape the next day.
- A tape contains some backups; when inspecting the tape, DPM says they are configured to expire the same day at 20:00.
- At 23:00 DPM can't use the tape because it says it's not free.
- The next day, backups on that same tape are successful.
Is this some sort of bug, or am I missing something here?
Do by chance DPM tapes expire on a daily basis, instead of at a given time in the day?