Just a guess-duh-mation on my part but....
     I have the same situation with my 3590 drives and upon looking at the
     general files on the tapes the only LOGICAL answer was/is that it is
     based on the amount of "end user space" that is packed onto the tape
     via software/hardware compression... I've had an an empty disk storage
     pool, backed up a 50GB data base and associated files, migrated that
     to the tape pool and it all goes on 1 3590 tape...
     I really should toot my horn more about cost effective these 3590's
     are... hmmm I do have one tape with 80GB on it... that makes it
     somewhere around 60 cents per GB  Ohhh but then I have to figure in
     the cost of the 3494 & 3590's  I might have to conveniently leave that
     out...
     later
          Dwight



______________________________ Reply Separator _________________________________
Subject: Tape utilisation question
Author:  ADSM-L at unix,mime/dd.RFC-822=ADSM-L\@VM\.MARIST\.EDU
Date:    10/1/96 8:27 PM


We are running ADSM V1 server on MVS.

When looking through the Admin GUI under Storage Pool Volumes, it shows
some tape volumes as having a different estimated capacity than others,
e.g :

Estimated Capacity (MB) Percent Utilised
428                             100
726                             53
673                             100
660                             49

We have one DEVCLASS for all tapes, which are all in a tape library.
The Estimated Capacity we specified when setting up the DEVCLASS was
800MB.

Can someone please explain what these figures actually mean and why they
appear to vary.