On 8/2/07, Anne Crabtree <[EMAIL PROTECTED]> wrote:
> We have five linux instances running, two of which aren't really being
> used, two are production and one is test.  In the test linux instance,
> they are running a web app (which I know nothing about).  At certain
> times during the day, this test instance will take close to 100% of the
> IFL.  We want to back it off so that it can take no more than 50% to see
> how that affects them.  Would it be logical to issue SET SHARE linux
> RELATIVE 50 since it is defaulting to REL 100?  Will that do what I
> think and limit it to half of what the other virtual machines "get"?

Really depends on what you want to achieve.
* When you set REL 50 and others have REL 100, the one with smaller
share will get only half of what another would get *if there is CPU
shortage*  It's something you do for test versus production servers
* If you want to "kneecap" the virtual machine to see what the
application behavior would have been when you did not have all that
spare capacity, then a share with LIMITHARD is useful (and you want
that absolute% because otherwise you have a moving target).

And for virtual machines with multiple virtual CPU's, you need to
realize share is divided by the number of virtual CPU's

When a virtual machine is looping or doing useless work that you want
to get rid of, then FORCE is more appropriate ;-)   But yes, I have
sometimes set virtual machines to REL 1 LIMITHARD to let them run
until I have time to start diagnose the problem.

Rob
-- 
Rob van der Heij
Velocity Software, Inc
http://velocitysoftware.com/

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