Good question.  Offhand, I can't think of anything that would cause it to
happen specifically to DBBackup tapes.

TSM will change the status of a tape from SCRATCH to PRIVATE if it has
trouble mounting the tape, so it can move on to the next scratch tape.

And I don't think the LastUse field is updated util the tape is used again
(unless the tapes are checked out).

But if it is a mounting problem, it should hit scratch pool tapes, too.

FYI, I have a script that once a month pulls a list of libv tapes and
stgpool tapes and compare them, to find tapes that are like this - i.e., no
valid data but in PRIVATE status caused by a mount failure.


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