Hi James,

If I understand well, every week, you backup 160 GB of data to new tapes
that are taken offsite ?

Have you tried to use backup STG. This command only put offsite the new
files. Say you have
1% of new files, you only have to offsite some GB and not some hundred GBs.
You do not need
to purchase DRM to do this, there are plenty of scripts that can helps you.

On your backup site, do you have a TSM server w/ a 3575 lib ? If yes, that's
is the solution,
you only move "week" data. Else, sometime, you will need to reclaim your
offsite tapes and
regenerates a full set of unfragmented-copy-tapes. I did this for a 8 TB
site and only a few tapes
(and DLT) are moved offsite every day.

As mentionned in the list, set the retention to 0. or scan IDLE drives an
manually dismount tapes
from a admin sched.

Hope this helps
Rv