We use a disk storage pool and migration to tape strategy also.  We only
have two drives in our 3575 library, so this allows many more backups to
run concurrently than if they went straight to tape and had to wait for
the drives.  Another advantage is the time that it takes to generate our
copy pool tapes.  While the data is still on disk it is backed up to
copypool, then it is migrated to tape.  Then when my backup of tape pool
to copy pool occurs there is very little data that needs to be copied
tape-to-tape (very slow).  ADSM knows that it already has a  copy of the
data from the backup of the diskpool, and doesn't copy it again.  This
will continue to work for me until we reach the point that our backups
require more disk space than is available in my diskpool, which will
cause migration to occur multiple times per day.  I am monitoring this,
and will add more disk when it starts to happen.

> -----Original Message-----
> From: Ann Courchaine [SMTP:acourcha AT CSC DOT COM]
> Sent: Friday, July 10, 1998 8:19 AM
> To:   ADSM-L AT VM.MARIST DOT EDU
> Subject:      backups to disk
>
> What is the general consensus on using a disk storage pool that then
> migrates to
> tape? Do sites actually use these or does everyone write directly to
> tape?
> Ann Courchaine
> Year 2000 National Practice
> Consulting & Systems Integration