Roger
Worth mentioning is that the issue is most likely compounded by the 
migration/reclamation process running during a backup, the performance hit  to 
the TSM server can be severe.
You may find a significant reduction in task processing times if you do isolate 
them.
In the past I have temporarily suspended (or limited) reclamation schedules 
until the initial backups are done and sent the backup data straight to my 
sequential storage pool bypassing the migration process.


-Rick Adamson


-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of 
Roger Deschner
Sent: Wednesday, February 17, 2016 8:43 PM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: [ADSM-L] Migration should preempt reclamation

I was under the impression that higher priority tasks could preempt lower 
priority tasks. That is, migration should be able to preempt reclamation. But 
it doesn't. A very careful reading of Administrator's Guide tells me that it 
does not.

We're having a problem with a large client backup that fails, due to a disk 
stgpool filling. (It's a new client, and this is its initial large
backup.) It fills up because the migration process can not get a tape drive, 
due to their all being used for reclamation. This also prevents the client 
backup from getting a tape drive directly. Does anybody have a way for 
migration to get resources (drives, volumes, etc) when a storage pool reaches 
its high migration threshold, and reclamation is using those resources? 
"Careful scheduling" is the usual answer, but you can't always schedule what 
client nodes do. Back on TSM 5.4 I built a Unix cron job to look for this 
condition and cancel reclamation processes, but it was a real Rube Goldberg 
contraption, so I'm reluctant to revive it now in the TSM 6+ era. Anybody have 
a better way?

BTW, I thought I'd give the 7.1.4 Information center a try to answer this. I 
searched on "preemption". 10 hits none of which were the answer.
So I went to the PDF of the old Administrator's Guide and found it right away. 
We need that book!

Roger Deschner      University of Illinois at Chicago     rogerd AT uic DOT edu
======I have not lost my mind -- it is backed up on tape somewhere.=====