Arnaud,
One point that may have been missed is not all jobs can be preempted. From
the manual:
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The following are high priority operations that can preempt operations for a
mount point:
Backup database
Restore
Retrieve
HSM recall
Export
Import
The following lists operations that can be preempted and are listed in order
of priority. The server selects the lowest priority operation to preempt,
for example reclamation.
Move data
Migration from disk to sequential media
Backup, archive, or HSM migration
Migration from sequential media to sequential media
Reclamation
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Note that things in the top list will preempt things in the bottom list.
The bottom list shows you in what order the preemption would happen. Or if
those jobs in the bottom were running at the same time which one would get
the boot.
Note that the jobs in the bottom don't preempt anything. So even though
Move Data has a higher priority that Reclamation it won't preempt a
reclamation job in order to run. However, if a restore comes along and all
drives are used by move data's and reclamations then a reclamation job would
get the boot.
Kyle
-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:[EMAIL PROTECTED]]On Behalf Of
Mark S.
Sent: Monday, February 19, 2001 14:24
To: [EMAIL PROTECTED]
Subject: Re: reclamation vs backup stgpool
Arnaud Brion wrote:
> I'm facing an embarasting situation since I changed the way our daily job
runs : I start a reclamation job, by decreasing the rec parameter to 50 % on
all storage pools every morning at 3:00.
> Two hours later I start a backup stgpool job, on all storage pools too,
and what happens is that most of the backup stgpool processes are waiting
for a free drive to begin.
> This should never happen, because of the preemption system included in
TSM, that avoids this kind of painfull sitation : backup of stgpools has a
higher priority than reclamation, so why do I have this problem ? (
nopreempt parameter is set to no)
> Did anybody face the same situation, and was it solved ?
There is documentation in the admin guides that show the priorities that
tape operations follow. Restores are at the top of the food chain,
followed by several others (including reclamation), with all backups
(including client and storage pool) at the bottom of the list. Whatever
is higher in the priority list will take precedence over those
operations that are lower.
This makes sense when you consider what is most important in a
backup/recovery system. Restores are the primary function, while cleanup
and bookkeeping jobs are not as important. As for backups, they can be
done anytime there is a drive available.
--
Mark Stapleton ([EMAIL PROTECTED])
