Manager [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
cc:
Subject: Re: DB Cache Hit Rate Question
I'm a little confused about the cache hit ratio information. If I run
expiration on a database, surely the TSM server has to trawl through the
entire thing on disk as it does not already
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Sent: Wednesday, February 19, 2003 11:15
To: [EMAIL PROTECTED]
Subject: Re: DB Cache Hit Rate Question
Can anybody tell me where I can locate a copy of the TSM 3.7 Technical Ref
Redbook.
I assume it is a seperate entity to the Admin Guide and Admin Reference.
Thanks
Farren Minns
John
Can anybody tell me where I can locate a copy of the TSM 3.7 Technical
Ref Redbook.
I assume it is a seperate entity to the Admin Guide and Admin Reference.
Farren - Yes... All redbooks are separate from the main manuals.
The redbooks are at http://www.redbooks.ibm.com .
There, you would
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Sent by: ADSM: Dist Stor Manager [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
cc:
Subject: Re: DB Cache Hit Rate Question
Farren,
I'm not sure exactly how the TSM database internals work, but typically a
database cache is populated with cache prefetch. This isn't _exactly_
...Should the cache hit rate consistently be above 98%? ...
In a single word: No. The 99%+ is the fairy tale objective.
You'll find numerous postings in the List archives advising of
the real world behavior of caches which, as you've seen with
Backups, cause the number to drop, as one should
I'm a little confused about the cache hit ratio information. If I run
expiration on a database, surely the TSM server has to trawl through the
entire thing on disk as it does not already reside in the buffer. So how
would I expect to see hit ratios of 99% or higher. I won't go into details
here as
Farren,
I'm not sure exactly how the TSM database internals work, but typically a
database cache is populated with cache prefetch. This isn't _exactly_
correct, but it'll do conceptually. The db goes to read one row (check a
file for expiration). That one db row request loads one or more
