Are you running with colocation enabled anywhere? For best reclaim
performance, I have found that having colocation enabled=yes on both
onsite and offsite pools works the best. Why? Reduction of tape mounts.
Cost? Need more tapes, especially in offsite pool.
Per pool:
Keep in mind that onsite reclamation is 1 process PER tape: find a tape
needing reclaim->mount tape->relocate data->dismount.
Offsite reclamation is 1 process for ALL tapes: find all tapes needing
reclaim->select tape x(these appear to be done in age order)->figure out
where all local copies of data are stored->until x is finished(mount
onsite tape->relocate data->dismount onsite->next local tape)->next tape x
(offiste tape)
So it's concievable and likely that one onsite tape could be mounted
several times because some of it's files are on multiple offsite tapes.
Al
"Brazner, Bob" <[EMAIL PROTECTED]>
Sent by: "ADSM: Dist Stor Manager" <[EMAIL PROTECTED]>
11/11/02 05:44 PM
Please respond to "ADSM: Dist Stor Manager"
To: [EMAIL PROTECTED]
cc:
Subject: Space reclamation of offsite copy pool takes forever
Reclamation of our offsite copy pool is taking forever. Right now, we
have
200+ volumes in that pool. Normally, threshold is set at 60% and I get
maybe 8 or 9 volumes returned after processing for 7 hours (on beefy AIX,
with TSM at 5.1.5). Lately I've tried setting the threshold at 99, then
98, then 97, etc., but I don't see much improvement in overall freeing up
of tapes. It appears that most of the time is taken up with mounting
input
volumes. Even though we have a 3494, I'd say 80% of the time is spent
waiting for tape mounts. Is there any way to get space reclamation to
free
up offsite tapes faster? Note, for my onsite tape pool, I do not see this
problem (e.g., I can easily free up 30 tapes in 5 hours or less).
Bob Brazner
Johnson Controls, Inc.
(414) 524-2570
