Good gosh, what is it with the "unload/reload" craze on here lately.
It's like...
Patient: "ya doctor, I have had a shortness of breath lately."
Doctor: "We better do open heart surgery!!!"
I have a large TSM environment, with 8 TSM servers, most of them
in the 75-80GB database range. Most of them have been in production for
5 years or more, some of them are going on 8 years and I have NEVER had
to do a unload/reload on a production TSM server.
I did do one in our test environment and was impressed with the
improvements in speed and size of DB, but found that it was short lived
and within 60 days we were back to the same backup-time ranges as
before.
With the 9 hours of downtime that was associated with an
unload/reload, it's not an option in our 24X7 production environment for
such a short-lived benefit.
Paul,
Sounds like perhaps a bottleneck at the log device. You might
have them check the EMC SAN to make sure that the write cache is turned
on. I would also check out a 'q logvol f=d" and make sure that the "Log
Pool Pct. Wait" value is 0 (or almost 0). If it is higher, it points to
log volume performance issue.
Ben
-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Rees, Chris (Corp)
Sent: Friday, July 01, 2005 4:44 AM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: Very slow DB backups
Hi Paul
A strange volume config indeed....
One thing I'd ask is when was the last time this server was
unloaded/reloaded ?
Chris
-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Paul van Dongen
Sent: Friday, July 01, 2005 11:38 AM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: [ADSM-L] Very slow DB backups
Hello All,
I was called to examine a TSM server in order to make some
suggestions to improve performance. Upon arrival, I found out a
not-so-standard configuration:
TSM 5.1.6.4 on HP-UX 11
DB: 208 GB split on 208(!) volumes of 1GB each spread on 4 LUNs on an
EMC box (95% in use)
Log: 10 volumes of 1GB each, all on the same EMC LUN
Diskpool: 101 volumes of 1GB each, all on the same EMC LUN
I know that splitting this server should be the best solution, and there
are other factors contributing to this big DB size, but I will stay away
from this for while.
The first I noticed is that there are two full DB backups being executed
each day. They go to a LTO device class, and are taking some 3 to 4
hours to complete, including a stange 5 to 10 minute "sleep" between the
backup command being issued and the actual start of the process. I tried
to minimize this by setting the log to rollforward and trying to take a
incremental backup. To my surprise, the triggered incremental (log
became 70% full) started, with the same delay described above, but began
to crawl, at 8000 pages per MINUTE. It would give me almost 4 hours to
copy the 7 or so GB!! Naturally, I went back to the fulls until I found
out what could be the problem.
I am trying to talk to the admin of this server to upgrade to 5.2 or 5.3
and to review their disk config, but would like to hear from you if
someone has been trough something alike, and of course the line of
action that was taken.
Thanks to all,
Paul
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