On 12/9/05, James Melin <[EMAIL PROTECTED]> wrote: > My VM guy here is saying that he read some place that having mini-disk > cache turned on for mini-disk volumes used by linux for system disk is a > good thing.
With current z/VM releases there are certainly cases where you have benefit of MDC for Linux minidisks. One would need to have a closer look at the configuration to see whether in your case it would be a good idea. > From what I can see I'm caching 550 megs in Central stor on average and 163 > or so megs to expanded. The only disks I could get him to turn off caching > for was my linux swap volumes. That's fair, because it is very rare for a swap page to be read a second time, so you would not often have an MDC hit. Have you considered swapping to VDISK rather than real disk and avoid the entire thing? > So who is right? Isn't it correct that turning off mini-disk caching for > the linux volumes is the recommended method? Wouldn't that free up memory It's recommended from what I recall, but not by me :-) > othwise used by VM for the caching? We're getting very close to making VM > page on a consistent basis. We're running 6 websphere servers in 6 gigs > real 1 gig expanded (I know it should be more. We just don't have it). You'd have to look whether you're paging because of contention under the 2G bar. For starters I would disabled MDC in expanded storage and use that purely for paging. And I suggest to see in your performance monitor whether you are doing a lot of page moves around the 2G bar. Rob -- Rob van der Heij rvdheij @ gmail.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
