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Re: cache hit rate
2002-08-21 10:43:18
On woensdag, augustus 21, 2002, at 09:46 , Sascha Braeuning wrote:
Hi all,
first I've to thank all participants for the amount of answers I got on
my
latest questions. Now I've got a new one which relates on the
bufferpoolsize and the cache hit rate on OS/390 TSM-Servers.
we use the following bufpoolsize: 32768
our chache hit rate: 97,7 %
I know from my training at IBM that a cache hit rate of 99 % and above
is
recommended. Is it possible, that a lower cache hit rate can cause
performance-problems? What is your experience?
MfG
Sascha Bräuning
Sparkassen Informatik, Fellbach
OrgEinheit: 6322
Wilhelm-Pfitzer Str. 1
70736 Fellbach
Telefon: (0711) 5722-2144
Telefax: (0711) 5722-1630
Mailadr.: sascha.braeuning AT sparkassen-informatik DOT de
Hi,
a too low cache-hit rate has severe impact on performance. I guess 98%
cache-hits or better is acceptable. Set the selftunebufsize in your
dsmserv.opt file to allow TSM to tune the size of its cache for better
performance (though i noticed setting it to more or less a sensible
default to start with helps a lot...)
---
Met vriendelijke groeten,
Remco Post
SARA - Stichting Academisch Rekencentrum Amsterdam http://www.sara.nl
High Performance Computing Tel. +31 20 592 8008 Fax. +31 20 668 3167
"I really didn't foresee the Internet. But then, neither did the computer
industry. Not that that tells us very much of course - the computer
industry
didn't even foresee that the century was going to end." -- Douglas Adams
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