On Mon, 2004-03-08 at 15:37, Kinnear, Mike wrote: > We use z/VM for a Linux environment. A Redbook, > http://www.redbooks.ibm.com/redpapers/pdfs/redp3661.pdf > <http://www.redbooks.ibm.com/redpapers/pdfs/redp3661.pdf> on page 7 says > you should have a 1.5/1 virtual to real ratio for Linux environments running > Websphere applications. We've been running fine at about a 4/1 ratio for a > few months. Recently we have put a couple of new instances up with 768M > virtual memory each and we are seeing some high paging periods as well as a > couple of loops in Linux paging modules. Has anyone experienced any pain in > this area?
Yeah: large images are big opaque blobs to VM, and if you have lots of them, and VM thinks they all have to be resident, and you have physical memory heavily overcommitted, you tend to get situations where it's hard to dispatch machines, because by the time it gets dispatched, some necessary piece has been swapped out. Do the machines really have to be that large? Even WebSphere rarely actually requires 768M. Adam ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
