On Nov 30,  9:45am, Mike Leuthold,              University of Arizona wrote:
> Subject: Performance problem with dsm, V2.1, AIX 4.1.3
> Hi...
>         I'm a new user of ADSM so forgive any silly statements I may make.
 I've
> just set up ADSM on a RS/6000, 590 running AIX 4.1.3 and a EXB 440 tape
library.
> I've set it up using 2 storage pools for backup and archive, one disk, one
tape.
>  I have the disk pool set so that files larger than 10M are written directly
to
> tape.  What I see is that when I fire up dsm and begin an archive, everything
> goes fine until it gets to a large file.  dsm asks if I want to store it to a
> offline and I say yes.  At this time, the tape library begins to mount the
tape
> and the cpu usage of the dsm goes to 100%.  From now on, the performance is
> terrible (300k/sec) and the cpu usage stays at 100%.  What do I have
> misconfigured to cause dsm to use all this cpu?  Thanks.

Mike
I think this is normal when you try to write directly to tape... rather than
buffering it to disk and then having it migrated to tape by ADSM.
I have always heard that ideally you should be able to put all or most all of
your data to disk first (archive or nightly backups) and then have a second
level storage pool defined of tape, and have ADSM migrate to the tape rather
than have the archive/backup go directly there.

Also- have you turned compression on for the client ?  That might help.
Susie