I think you misunderstand the concept of how TSM handles offsite storage. 50
clients and 2TB of data isn't really that much at all. You would not be
duplicating 60 3590E tapes *daily* and shipping them offsite. The total
number of tapes offsite should be roughly the same as the number of tapes
onsite (though this assumes similar configuration on both your primary pools
and copypool). The number of tapes you ship offsite daily (or weekly) is
more dependent on how much data you back up on a daily bases (incremental
file backups + any DB backups). Also any offsite tapes reclaimed will have
to be returned onsite.

So in essence, the backup stgpool command doesn't backup the entire pool and
put it in the copypool. It only backs up the files that have not yet been
copied from your pool to the copypool. On a daily bases this should equate
to roughly the amount of data you back up incrementally.

Gerald Wichmann
Sr. Systems Development Engineer
Zantaz, Inc.
925.598.3099 w
408.836.9062 c