I see messages like this from time to time on my VM Lpars that only run guest operating systems and have little to no CMS users. I think it may be because the VM scheduler can't really see what a "transaction" is inside the GOS. I think it may just be an artifact of VM having an earlier design point of support a lot of concurrent users that have a lot of think time, rather than a farm of GOSes.
________________________________ From: The IBM z/VM Operating System on behalf of Martin, Terry R. (CMS/CTR) (CTR) Sent: Wed 9/24/2008 10:54 PM To: [email protected] Subject: Re: Performance Question The REAL processors are running about 85% per (5 IFLs) and the virtual processors for this Linux host are running an average of about 90% per (4 Logicals). There is no CPU queuing that I can tell. I am not running any of the products you mentioned. This may not be a bad indicator I am just trying to find out what it really means since the default shipped is 1.000 elapse time not sure if that means much! Thanks, Terry ________________________________ From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On Behalf Of David Kreuter Sent: Wednesday, September 24, 2008 9:03 PM To: [email protected] Subject: Re: Performance Question hard to say for certain. Not a number I look at that often. How busy are the processors? Is there CPU queuing? The scheduler tries to classify around 80% of work as class 1; so fluctuations are rather common. Are you per chance running WebSphere, WPS or Domino servers? David Kreuter ________________________________ From: The IBM z/VM Operating System on behalf of Martin, Terry R. (CMS/CTR) (CTR) Sent: Wed 9/24/2008 3:42 PM To: [email protected] Subject: [IBMVM] Performance Question Hi I am trying to get a handle on all of the z/VM tuning knobs if you will and have a couple of questions: I see the following during heavy processing on the particular Linux host: FCXPER315A Cl1 time slice 8.939 exceeds limit 1.000 (Q1=02 Qx=26) I am using the default alert of 1.000 that is set in the PTK hence the alert. My question, is the fact that elapsed time which a class 1 user can spend in the dispatch list being 8.939 a high number and what is it really telling me? Does it represent a potential bottle neck? Thank You, Terry Martin Lockheed Martin - Information Technology z/OS & z/VM Systems - Performance and Tuning Cell - 443 632-4191 Work - 410 786-0386 [EMAIL PROTECTED]
