Prior to the VSE upgrade, what was your CPU utilization?

The IBM Performance documentation on VSE, shows about 10% increase in CPU when 
going from VSE/ESA 2.6 to z/VSE 4.1 (assuming everything else being the same).

I find that SET SHARE ABSOLUTE to be fine.  In you case, there are some batch 
jobs running in a VSE image.  That image, as it is not being capped, can take 
100% of the CPU, IF, it is available.  But with the other VSE images also 
having ABSOLUTE available, assuming that the "adjusted" share is sufficient for 
CICS operations, they should be fine.

"adjusted" share?
Take all your "set share absolute" numbers and add them.
If the total exceeds 100, then CP will "adjust" your shares down, all by the 
same percentage, so the total equals 100.  

When you calculate that number, you should adjust your "set share absolutes" to 
those numbers as that is the actual CPU % you are setting.

Now that you have that number, you have to ask, is that "share" sufficient for 
CICS operation on my production systems?  If not, those shares have to be 
adjusted upwards (and taking other shares down).

If you don't do that, then a batch job, running on one VSE will cause 
production CICS performance problems.

If the problem is the CICS in the VSE that is running the batch jobs, then you 
need to look at your PRTY SHARE settings within VSE.  If VM is ending up giving 
you xx% of the CPU, and when you "adjust" your shares, you may find that VSE is 
giving CICS only 50% of the processor.  Which is 1/2 of what VM is giving you.  
As you slice the slices, some slices (especially for CICS) can become too thin.

Tom Duerbusch
THD Consulting

Cross-posted to both VMESA-L and VSE-L mailing lists

Greetings,

We have just converted the last of our 5 VSE machines to z/VSE 4.1.0
(from
VSE/ESA 2.6.1) and are experiencing performance issues. My peak times
are
98-100% utilization and people are complaining about poor response
times.

I don't know whether it's because I am using CICS data tables more now
or
because of the additional CPU utilization for z/VSE.

Anyways, one question I have is the usage of the SET SHARE.

I have been using the 'SHARE ABSOLUTE' directory control statement for
each
of my VSE machines (giving say 38% to one machine, giving 29% to
another,etc...) with maximum share nolimit.

The problems seem to occur when batch jobs are run in these
predominately
CICS/TS systems.

I was wondering if maybe a SET SHARE RELATIVE technique would be more
effective and what you do in prioritizing virtual machines within the
physical machine?

Thanks,

Mike


__________________________________________________________

This email may contain confidential and privileged material for the sole
use of the intended recipient(s). Any review, use, distribution or
disclosure by others is strictly prohibited. If you are not the intended
recipient (or authorized to receive for the recipient), please contact
the sender by reply email and delete all copies of this message. To
reply to our email administrator directly, send an email to
[EMAIL PROTECTED]

Law of Cat Acceleration

  A cat will accelerate at a constant rate, until he gets good and
  ready to stop.

Reply via email to