Well, speaking from the land of painful experience, yes you can have TSM
overwrite a tape owned by another ACSLS application.  That said, I believe
that the longer answer would include the phrase "in some instances."  If all
of the applications lock the tapes they are using then I don't think TSM
will be able to grab one and I know that TSM locks the tapes that it uses.
My experience was with the STK CAM application.  That application does not
lock tapes it has used so it is possible for TSM to allocate one of CAM's
tapes and write all over it.  Not good.

You need to avoid gross library commands within TSM.  For instance, if you
issue a label libvol search=yes command you can have problems.  You should
use volrange= and specify the tapes you know TSM can have.  However, it is
possible to define a volrange that overlaps with tapes owned by another
application (yes, that's what I did) and have data go into the great beyond.

Careful procedures will prevent the problem.  Media management in a mixed
environment is always hard.  What's to stop someone from removing the
barcode label from a tape and replacing it with another, different label?
This would cause data loss completely independent of application software.
I've seen this happen in production environments with ensuing data loss.
There are no guarantees in this game.  The software does it's best but human
error can result in problems.

Kelly J. Lipp
Storage Solutions Specialists, Inc.
PO Box 51313
Colorado Springs CO 80949-1313
(719) 531-5926
Fax: (240) 539-7175
Email: lipp AT storsol DOT com or lipp AT storserver DOT com
www.storsol.com
www.storserver.com