Thank you Now that you mention it, Rob has told me that in the past at a SHARE. I sincerely wish I could use zVPS...8(.... I will continue to not take reality - virtual or otherwise - seriously.
Life is too important to be taken seriously - Oscar Wilde. -----Original Message----- From: The IBM z/VM Operating System [mailto:[email protected]] On Behalf Of Barton Robinson Sent: Friday, November 13, 2009 11:37 AM To: [email protected] Subject: Re: zVM CPU allocation As Rob and Alan have less blatantly stated, Linux CPU numbers are bogus in a virtual environment. The CPU reporting problem has been corrected in ESALPS (now zVPS) for those that want to use linux numbers for anything useful. If you don't have a mechanism to correlate the linux cpu numbers to reality, then one would not want to take the "virtual reality" too serious.... David Dean wrote: > On Thu, 12 Nov 2009 13:01:52 -0600, Alan Ackerman > <[email protected]> wrote: > >> Where are you getting the 99% number? Which version of Linux are you >> running? Older versions of Linux were fooled by the CPU being taken away >> and reported high values of CPU utilization in 'top' and elsewhere. >> >> If all the numbers are from PerfKit, they don't make sense. You cannot >> have 3 users running at 99% and have the 3 IFLs running at 10-15% each. >> Are you sure you are looking at the same time interval? If you are looking >> at both Linxu and VM tools, they may not match up. >> >> Alan Ackerman >> Alan (dot) Ackerman (at) Bank of America (dot) com >> >> On Thu, 12 Nov 2009 13:17:26 -0500, Dean, David (I/S) >> <[email protected]> wrote: >> >>> OK, this is for all you guys that understand the magic tunnel in which >> CPU processing (usage) flows from an IFL to a zLinux server. >>> We have a z10 running zVM 5.4 in a dedicated LPAR with 3 dedicated >> IFL's. We have approximately 30 zLinux servers. Using IBM PerfKit, I >> list all of the individual USER / zLinux CPU usages, each of which >> generally run in the 1 to 5 % range. These servers do of course peak >> higher but on average they are pretty low. We then take a look at the 3 >> IFL's and see usage of maybe 5% on each. Now, let's say we have a USER / >> server or two or three go berserk and peak CPU at 99 % for an extended >> period of time. We then look at the IFL CPU usages and all three have >> climbed to maybe 10 to 15% each. >>> How did the CPU get allocated? Is it always spread evenly across the >> IFL's, is that a setting? Why, if there were 3 USER / servers running at >> 99%, was more CPU not allocated from the 3 IFL's? Why did the IFL's >> decide to allocate X amount and go no further. >>> In the USER DIRECTORY I allocate storage but not CPU. >>> >>> >>> >>> >>> David M. Dean >>> Information Systems >>> BlueCross BlueShield Tennnessee >>> >>> >>> >>> >>> ----------------------------------------------------- >>> Please see the following link for the BlueCross BlueShield of Tennessee E- >> mail disclaimer: http://www.bcbst.com/email_disclaimer.shtm >> ======================================================================== > > ----------------------------------------------------- Please see the following link for the BlueCross BlueShield of Tennessee E-mail disclaimer: http://www.bcbst.com/email_disclaimer.shtm
