Rob, you said "You actually want your VDISK configured small enough that Linux re-uses the pages rather than take fresh ones. Over time, when there is some swapping, Linux will eventually use all the pages in the VDISK, so you want it to be not much more than you maximum swap requirement during the day."
I'm not familiar with fine points of linux swapping: you imply linux reports some previously used but now unneeded swap disk blocks as allocated even though they could be freed? That behavior matches my recent experience swapoff-ing a 80% full swap partition and not seeing its blocks end up allocated on remaining swap partitions when swapoff finishes. That will make discovering my maximum swap requirement even harder as the reported swap blocks allocated can be much greater than swap blocks needed. -------------------------------------------------------- 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----- From: Linux on 390 Port [mailto:[EMAIL PROTECTED] On Behalf Of Rob van der Heij Sent: Tuesday, October 09, 2007 6:12 PM To: [email protected] Subject: Re: high water mark for swap space used? On 10/9/07, Chris Young <[EMAIL PROTECTED]> wrote: > If you were using VDISKs for swap I think you could check the size of those > because they should grow but not shrink. In which case the highest level > the guest got to (since last logon) would be the current size of the VDISK. The resident pages for VDISK don't provide it either. Until the full VDISK has been used, it's more like the total pages swapped out since the start. Not the amount of pages swapped out at a give moment. You actually want your VDISK configured small enough that Linux re-uses the pages rather than take fresh ones. Over time, when there is some swapping, Linux will eventually use all the pages in the VDISK, so you want it to be not much more than you maximum swap requirement during the day. Rob -- Rob van der Heij ---------------------------------------------------------------------- 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
