No, they don't page everything out of memory.DFsort and DB2 coorporate nicely with RSM to see how much memory is available for DFSORT. If you have usually more than sufficient memory, DFSORT can easily take quite a lot of it. This does mean that RSM has to page out pages that do not cause problems to the application. This in turn does mean, that you should have a page configuration that can handle these bursts. Sizing page configurations is often neglected in configurations with lots of storage, while it is just more critical if RSM decides to optimzize memory usage on DFsort requests.
Again: the fact that DFsort acts differently on the new device could be caused by CFW. With CFW dfsort could decide to use SORTWKs, without CFW DFSORT could decide that this is too slow and use memory. Kees. -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Adams, Anne (DTI) Sent: Thursday, February 28, 2013 15:55 To: [email protected] Subject: Re: DFSORT Weirdness Changes in paging activity? Okay, THAT did change when this occurred. We page like hell bent for leather. Our page data sets fill up like crazy and NEVER empty. When these jobs run, they page everything they can out of memory. All DFSORT options are defaults - we're using DFSORT through DB2. Anne R. Adams DTI, Systems Engineering (302) 298 - 3196 -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Elardus Engelbrecht Sent: Thursday, February 28, 2013 9:44 AM To: [email protected] Subject: Re: DFSORT Weirdness Adams, Anne wrote: >We're experiencing some weird DFSORT behavior after replacing our DS8100 with >a DS8800. Immediately after we configured and then moved our page datasets to >a DS8800, a number of DFSORT jobs started consuming all available (and >sometimes not so available) memory. We noticed in the sort itself that while >we originally used 900M memory objects used as main storage and none for work >storage, it reversed after we started using the DS8800. Please show a sample DFSORT JCL and SORT OPTIONS. >Nothing used in main storage and 6000M memory objects in work storage. No >parameters where changed, no maintenance was applied, no one snuck in and >changed JCL, programs, utilities. Nothing happened except we put our page >datasets on the DS8800. We didn't move anything else. Really? Nothing? You did not mention any changes in paging activity? Is it ONLY your DFSORT jobs affected or other jobs too? >Any ideas what would cause that? One quick thing I can think of, is the response times of the disks including paging rates and your Storage Class SMS setting. Other than that, I would compare 'old' jobs and 'new' jobs. Also I would use RMF, for example, to compare workloads. Groete / Greetings Elardus Engelbrecht ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ******************************************************** For information, services and offers, please visit our web site: http://www.klm.com. This e-mail and any attachment may contain confidential and privileged material intended for the addressee only. If you are not the addressee, you are notified that no part of the e-mail or any attachment may be disclosed, copied or distributed, and that any other action related to this e-mail or attachment is strictly prohibited, and may be unlawful. If you have received this e-mail by error, please notify the sender immediately by return e-mail, and delete this message. Koninklijke Luchtvaart Maatschappij NV (KLM), its subsidiaries and/or its employees shall not be liable for the incorrect or incomplete transmission of this e-mail or any attachments, nor responsible for any delay in receipt. Koninklijke Luchtvaart Maatschappij N.V. (also known as KLM Royal Dutch Airlines) is registered in Amstelveen, The Netherlands, with registered number 33014286 ******************************************************** ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
