On 9/11/06, Dusha, Cecelia Ms. WHS/ITMD <[EMAIL PROTECTED]> wrote:
Are you saying the MDC READS - 142/SEC could be driving the page space used to 55%? The paging rate itself is 1/SEC... We added 2 paging volumes to ensure the system does not run out of paging space.
I'm not sure he implied that, but it is certainly true. With the default MDC settings CP is often too agressive in using MDC that it actually causes paging to occur. Paging with 2000 per second is quite impressive with just a single page pack... Maybe on your previous system your backup was held back more than it did not cause MDC to grow that fast. You'd want to know what portion of real memory was used by MDC when you were paging that much. A performance monitor allows you to review various metrics during the event to understand what happened. Going from z/VM 3.1 to z/VM 5.1 is a giant step, and most likely even more changed at the same time. It's very hard to do this right with just a few CP commands after the thing happened.
Our production system is a guest system under z/VM 5.1. I don't know if this would matter in the explanation as to why the system had a 55% paging space utilization...
That's probably a wise thing to do. BTW did someone steal a cylinder from you? ;-) -- Rob van der Heij Velocity Software, Inc http://velocitysoftware.com/
