I think I would try playing with the thresholds a little more.  Maybe
going for a middle ground?  If you empty the diskpool before backups
start, and then set the threshold to say hi=60.  Hopefully migration
would then be done frequently, but not constantly, and could keep the
disk free enough that none of the backups would have to wait.  With a hi
set to a higher number (like 95%) your pool may get too full before it
starts, and migration could not free up space quickly enough (re your
first note).

If the migration process itself is actually slowing up the backups, I
don't suppose there is any chance of rearranging the backup schedules to
accomodate for scheduled migration between backups during the night?

> -----Original Message-----
> From: Roger Hohmann [SMTP:roger_hohmann AT WESTLB DOT DE]
> Sent: Friday, July 17, 1998 12:35 PM
> To:   ADSM-L AT VM.MARIST DOT EDU
> Subject:      Re: Controlled migration
>
> Thankx very much for your responses, but: my problem seems to be
> little
> challenging:
>
> In our shop ADSM is backing up 50 - 100 Gig per night (not examining,
> backing up!) using 12 Gig disk pool, and I noticed round 15 migration
> processes moving 35-70 Gig of data (some mgmtcls are direct to tape)
> the
> whole day. We can get some more disk space, but never up to 100 Gig.
> I'm
> afraid I run into bottlenecks when multiple clients are backing up the
> same
> time ADSM is migrating disk pool (like last night) and all slows down.
> So I
> have to control migrating data at night, while backups are running.
> With
> upd stgp HI=1 I expect high degradation on running backups while
> migration
> is on. Due to these conditions, I would like to test "move data
> dest=tape"
> for migration purposes at night, did anyone try this before?
>
> Regards
> Roger
>
> >We are using adsm v.3 with disk and tape storage pool. When our disk
> pool
> is nearly at high threshold and multiple backup schedules are
> starting, our
> disk pool likes to overflow >because the migration processes can't
> move the
> data as fast as needed to tape. The backup and migration processes are
> interfering, backup becomes sloooow.
> >
> >I would like to empty my disk pools before backup starts. May I
> switch hi
> threshold to 0 to start migration and then switch back or should I use
> "move data"? Does anyone know? Any >other ideas?
> >
> >Thanks in advance
> >
> >Roger Hohmann
> >
> >WestLB
> >Tel.: +49211 826 8155