We initially got bit on this with the DIRMC storage pool, but I installed
TSM at a site where their concern was restore speed and we elected to turn
on CACHE for the disk storage pool. Turns out that their estimates of how
much data would be backed up a day was too high and they ended up being able
to keep almost a week's worth of data CACHE'd on DISK. So on the weekend
when the COPYPOOL reclamation started, it would still be running 48-hours
later with no end in site. Working with the client, we turned off CACHE, but
to help on the restore speed I moved the MIGRATION tasks to the end of the
day, around 5:00pm. That way restores from last nights' backups would come
from disk, and that was the majority of their restores....users trashing
their file and want it back from yesterday.

We ended up using this as a model for other sites we manage and moved the
MIGRATION tasks to later in the day, but well before the backup windows
start.

Bill Boyer
DSS, Inc.