I made the mistake of believing what I was told. cp q storage 05:57:21 STORAGE = 2G Ready; T=0.01/0.01 05:57:21 cp q virtual storage 05:57:35 STORAGE = 128M Ready; T=0.01/0.01 05:57:35 cp q srm 06:01:42 IABIAS : INTENSITY=90%; DURATION=2 06:01:42 LDUBUF : Q1=100% Q2=75% Q3=60% 06:01:42 STORBUF: Q1=300% Q2=300% Q3=300% 06:01:42 DSPBUF : Q1=32767 Q2=32767 Q3=32767 06:01:42 DISPATCHING MINOR TIMESLICE = 5 MS 06:01:42 MAXWSS : LIMIT=9999% 06:01:42 ...... : PAGES=999999 06:01:42 XSTORE : 0% Any recommendation for LDUBUF? I just raised it to 100 100 100. Please advise if that change was counter indicated. Thank you, Dave O'Brien National Institutes of Health
________________________________ From: Gentry, Stephen [Sent: Thu 3/20/2008 2:51 PM Subject: Re: Performance problem Linux under Zvm What command did you use to determine that you had 768m central storage? QUERY STOREAGE? QUERY VIRTUAL STORAGE? Steve G. -----Original Message----- Subject: Re: Performance problem Linux under Zvm Thanks John cp q srm IABIAS : INTENSITY=90%; DURATION=2 LDUBUF : Q1=100% Q2=75% Q3=60% STORBUF: Q1=300% Q2=200% Q3=200% DSPBUF : Q1=32767 Q2=32767 Q3=32767 DISPATCHING MINOR TIMESLICE = 5 MS MAXWSS : LIMIT=9999% ...... : PAGES=999999 XSTORE : 0% Just got the following from one of the other techs (non-VM) We were able to diagnose the problem and make the necessary correction. The problem was z/VM has a total 768m of central available. The Linux guests (3 total) each had 768m of central allocated, therefore contention. The Linux guests are over allocated and are storage constrained with 768m of central. Understanding the Linux guests would be in contention with each other for this storage VM time sliced what it could for each guest, therefore the symptoms we experienced. My question to this group - Does a Linux quest really require 768MB of Central? Regards, Dave O'Brien ________________________________ From: Romanowski, John (OFT) Subject: Re: Performance problem Linux under Zvm If CP INDICATE QUEUES shows an En (like E3) in the 2nd column for one or more userids try CP QUERY SRM (write down response for reviewing ) and do this quick fix CP SET SRM STORBUF 300% 300% 300% -------------------------------------------------------- This e-mail, including any attachments, may be confidential, privileged or otherwise legally protected. It is intended only for the addressee. If you received this e-mail in error or from someone who was not authorized to send it to you, do not disseminate, copy or otherwise use this e-mail or its attachments. Please notify the sender immediately by reply e-mail and delete the e-mail from your system. -----Original Message----- Subject: Performance problem Linux under Zvm Our shop is new to Zvm and Linux. We have a very small number of Linux users who are reporting significant response time problems. It almost seems as if each stops running for a period of time and is then re-dispatched. Is there a VM parameter that we might have taken the default on that needs tweaking? Any help or advice appreciated as this is a proof of concept endeavour and we would like not to turn off prospective users from the start. Thank you, Dave O'Brien National Institutes of Health
