Tapes dissapeared from pool / unknown tapes
Posted by Sven Koester, Last modified by Andre Kuehnemund on 13 May 2016 19:46

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:

  1. A backup job in PresSTORE found no more empty tapes and decided to recycle volumes.
  2. 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.
  3. PresSTORE started the label process, but either a write error occurred or the verification of the written data failed
  4. The label job attempted four times to repeat the above operation but failed to label the tape.
  5. 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.

 

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Comments (4)
Neto, J.B.
10 May 2016 16:22
how do I solve this problem? We lost one of our lto tapes, and Media Management - Volumes is just showing the Label bar code related to lost lto tape, with the following message : Drive 1 :: Transporter 1.
Please! I need help!
Thank's.
Andre Kuehnemund
13 May 2016 19:47
@Neto: Please open a support ticket, attach the support data from your P5 server (see P5 manual for instructions) and also provide us with the date and time the issue occurred. We can then look at the logs.
Chris Wetzel
20 July 2016 17:34
"If all else fails, check whether it is possible to label new tapes."

Is this suggesting tapes may need to be replaced? Or do we just need to relabel the existing tapes?
Andre Kuehnemund
31 August 2016 18:28
It depends on why P5 failed to relabel/recycle a tape. The older tape itself may have been just fine and a mechanical tape library error or a bus reset error may have caused the recycling to fail. In such a case, trying to relabel that tape again may be all that is needed.
If the tape itself is worn or in case the tape or the cartridge are damaged - and that's why the relabel/recycling failed - then you would need to try to replace the tape.
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