Paging (if you'll pardon the pun :-) ) Don Deese and wondering what checks he has in CPExpert in this area. Might provide inspiration to z/OS Development - if Barbara's comment had spurred them to revisit this area.
Cheers, Martin Martin Packer, Mainframe Performance Consultant, zChampion Worldwide Banking Center of Excellence, IBM +44-7802-245-584 email: martin_pac...@uk.ibm.com Twitter / Facebook IDs: MartinPacker Blog: https://www.ibm.com/developerworks/mydeveloperworks/blogs/MartinPacker IBM Mainframe Discussion List <IBM-MAIN@bama.ua.edu> wrote on 04/02/2012 16:03:22: > From: > > Barbara Nitz <nitz-...@gmx.net> > > To: > > IBM-MAIN@bama.ua.edu, > > Date: > > 04/02/2012 16:35 > > Subject: > > Re: Very Lage Page Datasets (was ASM and HiperPAV) > > Sent by: > > IBM Mainframe Discussion List <IBM-MAIN@bama.ua.edu> > > Charles, > > >I believe you're referring to the ASM_LOCAL_SLOT_USAGE check. > Yes, I do. > > > If so, this check runs at a 30 minute interval and checks the slot > usage for each in-use local paging data set regardless of whether it > was defined 'statically' or added via PAGE ADD. So... it does > eventually recognize a changed configuration. Some of the ASM checks > are set to re-run when a PAGE ADD/DELETE is issued, but > ASM_LOCAL_SLOT_USAGE is currently not one of them. Open to suggestions.... > > As far as I am concerned, there is 'intelligence' missing in that > check (my usual complaint with health checks). > > In our installation, we only have one device geometry, behind the > same controller, and all page data sets are same size. So I expect > the health check to recognize that adding a page ds to the overall > config will relieve the 'performance impact' of 30% overall usage. > Unfortunately, ASM does NOT prefer the new page ds, it is one of > many, and as I indicated before, has never filled to the same slot > usage as the others. Only IPL has ever evened out slot usage (and I > am not talking about 1% difference, more like 20% difference on the > same geometry and size! I think Skip mentioned this, too.) > > So the old, already-at-30%-usage locals and the new one are treated > equal, so slot usage on the old ones increases over the 30% mark, > and the check would still trip every 30 minutes because of that (if > I hadn't set it to only check once per day until the next IPL). > After it had alerted us to the condition once, it becomes basically > useless for the life of the IPL. > > In my opinion, this health check should have the intelligence to > recognize something about the configuration (same controller, same > size data set) and change the checking parms accordingly, especially > when a page data set was added. The check should obviously (as Kees > indicated) behave differently if different percentage slot usage is > due to different geometry and/or different size page ds. > > Now that I have established a daily graphic that shows slot > utilization (as shown by Barry via MXG), I might get rid if that > check completely and check my graphic instead. :-) > > Barbara > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@bama.ua.edu with the message: INFO IBM-MAIN > Unless stated otherwise above: IBM United Kingdom Limited - Registered in England and Wales with number 741598. Registered office: PO Box 41, North Harbour, Portsmouth, Hampshire PO6 3AU ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: INFO IBM-MAIN
