You can achieve the same generally by using the SHARE settings with the
ABSOLUTE and RELATIVE options carefully for each machine. We run DB2 and
multiple production, Test, and Public access webservers as well as Batch
COBOL in a pure VM environment and have very little problems with
performance even running for hours at a time at 100%. DB2 is a key factor.
Using a low dispatcher bias allows DB2 to better manage batch requests over
higher priority on-line. I keep DB2 and file servers at a high share rate
with an absolute setting of 70%. This leaves the rest to insure that batch
and dispatching of the webservers actually get something done. Batch can be
overwhelming since all of it is static SQL while the webserver CGI's are
all dynamic. It would be easier if that were the other way around.
Performance monitoring has to be the rule. Just as in the zOS world things
can always get out of control when one aspect or the other get to busy.
Steve Domarski 352-368-8350
Property Appraisers Office Marion County Florida USA
"Great minds discuss Ideas.
Average minds discuss events.
Small minds discuss people. " - Admiral Hyman Rickover
Richard Heritage
<[EMAIL PROTECTED] To:
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DU> cc:
Sent by: The IBM Subject: CPU Utilization Limit
z/VM Operating
System
<[EMAIL PROTECTED]
UARK.EDU>
10/25/2006 12:30
PM
Please respond
to The IBM z/VM
Operating System
I know this is an "it depends" question, but I hope some of you can give
me a very general answer. As an MVS guy, I'm used to being able to run
the processor very close to or even at 100% without significant
performance degradation. Assuming that everything is configured and
tuned properly (a big assumption, I know), can VM drive the processor
the same way? Our application people are used to other platforms that
don't tolerate high CPU utilization so well and think things are going
to start falling apart when we hit 80%. I'd like to reassure them--but
only if it's accurate to do so! This is a WebSphere application running
on multiple SUSE instances, with the data on DB2 under z/OS. Is it
reasonable for me to expect--again, assuming everything else is
right--to be able to run at 90+ percent without problems?
Richard Heritage
Lead Systems Software Engineer
IT @ Johns Hopkins
