We use 3590 J's and K's.  I've been asked what the lifespan of these tapes
are.  I've seen where the shelf life might be 10-12 years, but have not been
able to find anything about the regular use of them.  Our tapes are returned to
scratch when they become empty, so they are not private tapes.  It's my
undertanding that we lose the number of mounts for the tape when it is moved
from scratch into a private storage pool.  Is there a way to track it's usage
and and know when it's reaching it's maximum lifespan?  Is there an approximate
lifespan for these tapes when used regularly?  Or do I just wait until IO
errors start occurring and remove it then?

Thanks,

Diana