On Tue, 14 Jan 2014 09:29:12 -0600, David G. Yeager <[email protected]> wrote:
>I don't think I've posted to this list in some time. Usually I can't take >the heat. But you were all so nice to they guy applying maintenance to his >running system, so I figured to give it another shot before I drop off the >grid. Asking the author of the latest IBM red paper about it, it sounds >like I should probably have left it alone but I chose to increase our 16K >classdef to 32K classdef with the thought that I could spare some storage for >buffers over what I read is some CPU consumed making the 16K buffers into 32K >buffers. I did this even thought I'm still fuzzy on how it all works and can >find very little information on it myself. For instance if some product >stalls pulling buffers off the input structure does that gum up the works ?. >Good luck I say. I use 32K buffers for one of my classes. /* MAXMSG SHOULD BE HIGH ENOUGH FOR AT LEAST 30 MESSAGES/BUFFERS */ /* DEFAULT MAXMSG WAS 750 (CHG IN OS/390 R2 FROM 500) */ /* DEFAULT MAXMSG IS CURRENTLY 2000 (CHG IN Z/OS 1.7 FROM 750) */ CLASSDEF CLASS(DEFAULT) CLASSLEN(956) GROUP(UNDESIG) MAXMSG(2000) CLASSDEF CLASS(XCF8K) CLASSLEN(8124) GROUP(UNDESIG) MAXMSG(2000) CLASSDEF CLASS(XCF32K) CLASSLEN(32700) GROUP(UNDESIG) MAXMSG(2000) CLASSDEF CLASS(XCF61K) CLASSLEN(62396) GROUP(UNDESIG) MAXMSG(2000) (I don't know if my comment in the COUPLExx member about 2000 being the default is still true, but I think it is) The classes were set up (many years ago now) were based on my particular workload at the time and what I saw in RMF reports and results from "D XCF,CD,CLASS=ALL" across the sysplex. XCF is _much_ better at self tuning than it was in the early days and you can probably just have 956 and a 32K class (for example - always have the 956 default and some bigger class - 16K or higher). -- Mark Zelden - Zelden Consulting Services - z/OS, OS/390 and MVS ITIL v3 Foundation Certified mailto:[email protected] Mark's MVS Utilities: http://www.mzelden.com/mvsutil.html Systems Programming expert at http://search390.techtarget.com/ateExperts/ ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
