This is something we're looking at. There's some risk getting into such a situation if ...
a) you significantly overcommited your memory, and b) you have oversized Linux images (more than the application working set requires), and c) the images are "rather busy" Then from a VM perspective it is hard to determine a page that can be selected for paging in case of memory pressure, if everything appears to be ongoingly in use ... If the sum of the images requires that much storage for its working set (other than I/O buffering), and are busily active, then there is little we can do, though. Then you must not excessively overcommit your memory. There is some thought, oversizing Linux memory to be prepared for arbitrary peak workloads, thinking VM could page more efficiently. You may choose to have Linux use its memory more restrictive, and let Linux page in case of memory pressure instead. Depends on the workload ... Best regards, Ingo -- Ingo Adlung, Linux for zSeries - Strategy & Design The box said, 'Requires Windows95 or better', ...so I installed LINUX. Barton Robinson <[EMAIL PROTECTED]>@VM.MARIST.EDU> on 25.04.2002 16:48:30 Please respond to Linux on 390 Port <[EMAIL PROTECTED]> Sent by: Linux on 390 Port <[EMAIL PROTECTED]> To: [EMAIL PROTECTED] cc: Subject: Re: [LINUX-390] LinuxWorld Article series The author is correct. This has NOT been addressed for Linux on zSeries. >From: Werner Puschitz <[EMAIL PROTECTED]> > >Is the author right on this: > >http://www.linuxworld.com/site-stories/2002/0416.mainframelinux-p7.html >"Linux memory management assumes control of a machine and so grabs up >free memory for use in I/O buffering. Having multiple Linux instances do >this to independently buffer I/O to the same files resident on a shared >mini-disk not only wastes memory, but dramatically increases the paging >effort." > >Or has this already been addressed for Linux on zSeries? > >Thanks >Werner "If you can't measure it, I'm Just NOT interested!"(tm) /************************************************************/ Barton Robinson - CBW Internet: [EMAIL PROTECTED] Velocity Software, Inc Mailing Address: 196-D Castro Street P.O. Box 390640 Mountain View, CA 94041 Mountain View, CA 94039-0640 VM Performance Hotline: 650-964-8867 Fax: 650-964-9012 Web Page: WWW.VELOCITY-SOFTWARE.COM /************************************************************/
