Hi Frank,

> It would be of great interest to learn how other
> installations have configured their ADSM/UNIX systems, what
> kind of tape systems they run, what kind of performance their
> experiencing and so forth.

we run a RS/6000-590 with 512MB RAM and ~40GB disk. We run
the ADSM server and client on this machine using shared
memory communication method. The backup is done by using
incremental backup. We don't use archive because the client
(AIX 2.1.0.6) bails out when archiving symbolic links which
points to nothing and specifying subdir=yes. The ADSM database
is ~500MB big and the recovery log ~18MB. The data goes
to a 7331-205 tape stacker (with 2 tape drives) attached to
this machine. Unfortunately, the tape drives are not hot
swappable.
A full backup takes approx. 12 - 16h, an (daily) incremental
backup takes 1 - 2h. If we'd use archive to do a monthly archive
(provided that archive will finally work) and keeping the data
for 1 year in the tape library we'd blow up easily our tape
stacker. We use DRM to sent data offsite in case the worst
happens. I implemented recently HSM for test purposes, but what
I saw from these tests was not very encouraging. The tape drives
in the 7331-205 are much to slooowwwwww for HSM (it took over 1h
to move 1.7GB to tape (OK, the disk was also a little bit slow
(SCSI-2, 5400 RPM))).

Hope this helps,

Greetings, Lothar