According to The Quantum Manual:
CompacTapeIII and CompacTape IV
Shelf Life = 30 years at 200C & 40% relative Humidity
Usage 500,000 passes

Pat Wilson wrote:
>
> [ I could have sworn I'd seen something about this already, but
>   can't find it in the archives... ]
>
> I've set up a scheme where the first backup of any machine (these are
> multi-GB Unix servers, and I dump the whole OS) goes directly to my tape
> pool, which means I've got a few tapes sitting around that don't have a lot
> of reclaimable space on them.  What's your feeling on how long those tapes
> should go before I recycle them (by doing a "move data", I guess)?
> Naturally, the primary and copypool data is pretty much in the same state
> (the copypool tapes are aging and not being freed up, either)...
>
> Thanks.
>
> Pat Wilson
> paw AT dartmouth DOT edu