Since the ASM change to support large page data sets (z/OS 1.10, rolled back to 1.8 & 1.9 via APAR OA20749), we've been using full volume 3390-9 for locals and in some of our very large LPARs full volume 3390-27 volumes.
Since we couldn't support WLM PAVs in some environments (shared DASD between sysplexes), we've never had more than one local per volume. And as someone already mentioned, HIPERPAV doesn't address this (unless that code was fixed in 1.11 - I don't recall). I think was we migrated DASD the ROT was to put it on 3390-27 as long as there were at least 4 of them (to be the equivalent of the former space allocated on 3390-3). Mark -- Mark Zelden Sr. Software and Systems Architect - z/OS Team Lead Zurich North America / Farmers Insurance Group - ZFUS G-ITO mailto:[email protected] z/OS Systems Programming expert at http://expertanswercenter.techtarget.com/ Mark's MVS Utilities: http://home.flash.net/~mzelden/mvsutil.html On Thu, 21 Jan 2010 09:07:16 -0800, Ron Hawkins <[email protected]> wrote: >Cobe, > >I've never seen that suggested or recommended. As Mr Merrill says "Just >because you can, doesn't mean you should." > >Ron > >> -----Original Message----- >> From: IBM Mainframe Discussion List [mailto:[email protected]] On >Behalf Of >> Cobe Xu >> Sent: Thursday, January 21, 2010 8:17 AM >> To: [email protected] >> Subject: Re: [IBM-MAIN] Page Dataset Question >> >> IIRC, Isn't it suggested to allocate one Local on a full volume? >> >> On Thu, Jan 21, 2010 at 2:04 AM, Staller, Allan ><[email protected]>wrote: >> >> > This is a performance issue. In order for ASM not to care, the pages are >> > distributed (roughly equally) across all available page datsets. If the >> > algorithm were to take into account the available space: >> > 1) the additional overhead of keep track (probably miniscue per IO, but >> > imagine a paging rate of 100's or even thousands per second. (this >> > actually happened in "the good old days"). >> > 2) The concentration of pages in the larger page dataset would create a >> > "hot spot" in the aux stor subsystem and provide uneven performance, >> > depending on where your stolen pages were. >> > >> > >> > <snip> >> > Wouldn't it make more sense if "distributed equally" were defined as a >> > percentage of available space rather than number of pages? >> > </snip> >> > >> > All this does is allow for human error if the page ds's are not sized >> > equally! >> > >> > ---------------------------------------------------------------------- >> > 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 >> > >> >> >> >> -- >> Cobe Xu >> >> Best Regards >> ----------------------------------------------------------- >> zOS Performance & Capacity Analyst >> E2E Performance Analyst >> Email: [email protected] >> ----------------------------------------------------------- >> > >---------------------------------------------------------------------- >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
