When running a scheduled backup, the tapes holding the data belong to at least one media pool. Usually the number of tapes is calculated to hold the required size plus a little spare room. In case some tapes are missing, the backup may end up being incomplete.
Under some special conditions, it may arise that some tapes, even if located in the media changer and accessible by PresSTORE, are shown as "unknown" and ignored by PresSTORE. This is often the result of a problem that arose while PresSTORE attempted to recycle tapes. This is what probably happened:
- A backup job in PresSTORE found no more empty tapes and decided to recycle volumes.
- Before recycling, the tapes are cleared from indices and removed from the media pool. Now the tapes were unknown and PresSTORE tried to label the tapes and to add them with new labels to the media pool.
- PresSTORE started the label process, but either a write error occurred or the verification of the written data failed
- The label job attempted four times to repeat the above operation but failed to label the tape.
- The job gave up, the tape remained in the jukebox but is unknown for PresSTORE because it could not be labeled.
What to do now:
- The start of the tape is the most stressed part of the tape, so errors on the tape will most probably first on the tape. Try to clean the tape drive and retry to label the tape.
- In case multiple tapes failed at the same time, check whether the tape transportation or the mounting of the tape failed and there is a systematic hardware problem in the jukebox.
- If all else fails, check whether it is possible to label new tapes.