Dave, I would concentrate on MDC iso. PAV for VSE-fullpacks. When we started using MDC for VSE-dasd, we saw a real boost in throughput even though our real dasd already had quite a large cache.
Once MDC has been activated, you can use a monitor (or QMDC EXEC, written by K. Buelens, should be on the VM-download pages) to get an idea of the MDC hit-ratio per minidisk. Keep MDC on for fullpacks with good hit-ratios, and turn it off for the really bad ones. You could even re-arrange your VSE-files onto mostly-read fullpacks vs. mostly write minidisks. We use about 800MB for MDC (no xSTORE). Using more storage didn't really help. A good example for MDC success is the fullpack where DOSRES and SYSWK1 reside: it has an average MDC Hit ratio of 96%. Some of our database(IDMS) fullpacks get >90% as well... Just give it a try. Bye, Geert. -----Original Message----- From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On Behalf Of Dave Reinken Sent: maandag 19 maart 2007 21:19 To: [email protected] Subject: PAV and VSE guest I was recently reviewing this: http://www.vm.ibm.com/storman/pav/pav2.html at the behest of my manager. He is looking to extend the life of and better utilize our current hardware. We are running z/VM 5.2 on a z800, with a single z/VSE 3.1.2 guest, using Shark 2105-F20 disk. We currently use DEDICATED volumes for z/VSE. I am not necessarily against changing these volumes to minidisks if there is a performance benefit to be gained. However, from my reading of the above referenced article, it appears to me that converting them to minidisks and running PAV is going to gain me about ZERO, since all I have accessing the disks is a single z/VSE guest. Is this true, or am I missing something and should look into PAV and minidisks for my single z/VSE guest? It looks to me that multiple z/VSE guests sharing volumes on minidisk _may_ benefit from PAV under VM, but a single one won't. DISCLAIMER This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify [EMAIL PROTECTED] This footnote also confirms that this email has been checked for the presence of viruses. Informatica J.Van Breda & Co NV BTW BE 0427 908 174
