Cyndi Flis wrote, in part..

> When we looked into colocation we analyzed tape reclamation.  BIG SURPRISE!
> Having many clients on one tape can cause MANY mounts.

ADSM is just trying to do the collocation well.

Since we have no robot/library and quite vocal operators, we try to
minimize tape mounts.  :-)   However, restores of relatively mature
filesystems from a non-collocated pool can take MANY TIMES the elapsed
time of the same restore from a collocated pool.

So we have taken a multi-pronged approach:

* Business-critical nodes use a collocated pool, whereas individual
  desktops and non-critical servers use a non-collocated pool.

* We dedicate as large a disk storage pool as possible for staging
  backup data.  The staging pool for the collocated pool is
  significantly larger than the one for non-collocated data.

* We allow tapes to become relatively empty before reclaiming data
  (<20%).

* We don't let ADSM do reclamation, but do MOVE DATAs back to the
  staging area. We have tapes with much smaller capacity (3480-200MB),
  so with your much larger capacity tapes, your staging areas would
  need to be relatively large.

Hope this helps,
wayne

Wayne T. Smith               mailto:wts AT maine.maine DOT edu
Systems Group -- CAPS        University of Maine System