My response is not directly to this posting, just my comments to the original question. I do not have the original post. First, I have to ask what is more important to you? Is it SORTs or your online systems? I will assume online. We had problems with large sorts impacting our online. CICS is usually storage protected, so it was not impacted. We run Websphere Application Server and this was badly affected. WAS is not storage protected and uses a lot of memory. So it was a prime target for page steals. After the sort started we had high page-in rates for WAS. This was an issue. We looked at DFSORT options and decided we wanted to stop the page steals.We changed the EXPOLD parameter to zero, The default is MAX. This means that now DFSORT will only try to use available memory and not steal unreferenced pages from other work. If you are looking to make SORT fly then you may want to leave DFSORT to steal pages. But we want our on-line systems to perform and so DFSORT is a low priority. At the time of our problem we were storage constrained. Not paging, but low available frame queue. We added more memory and now have a lot free. We still do not allow DFSORT to steal pages though. On paging, I come from the school that I do not want to page. If I could restrict to very low priority work then maybe a little paging. The cost of memory means that you get more benefit from adding memory than messing around with the paging subsystem. Yes I want a paging subsystem that can handle large paging, but I do not want to use it. Its there as insurance. Also beware of free memory depletion when you take an SVCDUMP. This can hit you the same way.
Terry Draper zSeries Performance Consultant [email protected] mobile: +966 556730876 --- On Tue, 19/1/10, Staller, Allan <[email protected]> wrote: From: Staller, Allan <[email protected]> Subject: Re: DFSORT memory used & paging To: [email protected] Date: Tuesday, 19 January, 2010, 13:19 Page out is asynchronous and will only affect paging performance to the extent that the channel/device is not available for demand page-in. <snip> By %USE I meant page slots used, meaning increase in page out. > Why does workflow drop from %use? too much juice wasted on paging out/in. The issue is not page config, but increase in paging out/in & drop in workflow. </snip> ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
