Re: Performance problem with dsm, V2.1, AIX 4.1.3
1995-11-30 13:04:56
Subject: |
Re: Performance problem with dsm, V2.1, AIX 4.1.3 |
From: |
Susan McClure <smcclure AT IS.RICE DOT EDU> |
Date: |
Thu, 30 Nov 1995 12:04:56 -0600 |
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
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