I was doing free -m to make it easier to read.. Thanks for the info, one of our DBA's suggested that perhaps what is being swapped out is unused buffer pool pages, they have had to define lots of them to handle certain high volume events but much of the time they would be inactive, this kind of fits what you are suggesting as well. that the kernel is sending the idle pages away, so it sound like what I need to do is reduce memory further and ensure I have enough vdisks to cover their buffer pools...
Any ideas on how I might "snoop" around in the swap disk to figure out if this is the case? ------------------------------------------- Jeremy Warren Sr. Systems Programmer KB Toy Stores 100 West St. Pittsfield, MA 01201 (413) 496-3900 mailto:[EMAIL PROTECTED] "Post, Mark K" <[EMAIL PROTECTED]> Sent by: Linux on 390 Port <[EMAIL PROTECTED]> 09/15/2004 04:09 PM Please respond to Linux on 390 Port To: [EMAIL PROTECTED] cc: Subject: Re: [LINUX-390] Identify who / what is swapped out Jeremy, Those numbers look kind of strange. On my SLES8 system, the values are in KB, not MB. Hate to ask, but are you sure you have 750+MB of space on that system? (Although if you didn't, I can't imagine how the system got booted with on 755KB of virtual.) But, to answer your question, Linux will swap out unused pages in preference to having buffers and cache in storage. It's only when unused pages are swapped out, and more storage is needed that it starts trimming buffers and cache. It would be a little unusual to have 256MB of unused pages out on swap, though. Mark Post -----Original Message----- From: Linux on 390 Port [mailto:[EMAIL PROTECTED] On Behalf Of Jeremy Warren Sent: Wednesday, September 15, 2004 3:58 PM To: [EMAIL PROTECTED] Subject: Identify who / what is swapped out I have what I think is an odd situation, maybe it's my ignorance hanging out again... I have a linux guest with 2 vdisk swap disks at different priorities, plus 764MB of real memory (Reserved in VM so it's really real...) What I don't understand is why I have seen, fairly often, occasions where all of my swap disks are full, even though there is 370MB of buffers/cache... I thought linux considered swap evil and wouldn't put things out there unless it HAD to.. This sample isn't quite "full" but shows the basic idea.. linux2:/var/log # free -m total used free shared buffers cached Mem: 755 741 14 0 31 330 -/+ buffers/cache: 378 376 Swap: 253 243 9 So in my naive view of the universe, I should be seeing cached at about 87MB, or so and swap at 0 used, 253 free... Since there shouldn't be any need to put anything out on swap...I have enough real memory... I have seen it where swap is totally full (0 free) with similar numbers for the -/+ buffers/cache: line. I guess I am trying to find a way to "query" the swap infrastructure to try and determine what was out on swap at a particular point in time to try an whittle down this behavior, or at least better understand what is going on.. If it matters this box is SuSE SLES8, and running db2 udb version 8. Thanks in advance! Jeremy ----------------------------------- Jeremy Warren Sr. Systems Programmer KB Toy Stores mailto:[EMAIL PROTECTED]@kbtoys.com ---------------------------------------------------------------------- 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 ---------------------------------------------------------------------- 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 ---------------------------------------------------------------------- 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
