IBM Mainframe Discussion List <[email protected]> wrote on 03/03/2008 01:21:02 PM:
> Rob, > > Definitive answers need to come from IBM since this is not yet generally > available service but my impression is NO. This APAR is specific to > Large Page Datasets. The DFSMSdfp changes were already in place. There > was a WSC FLASH10550 that warned people that even though the DFDMSdfp > limitation for page data sets was removed the z/OS ASM componenent had > not been updated to use more than 4G in a data set. This APAR is > updating the z/OS ASM to use all the space that it can without expanding > fields in the ASMVT that would have an unacceptable impact to customers > and ISV's to be shipped into the service stream. > > This is the FLASH I mentioned. I expect once the PTFs for OA20749 are > available it will be revised. > > http://www-03.ibm.com/support/techdocs/atsmastr.nsf/WebIndex/FLASH10550 > > z/OS: ASM Support for Large Page Data Sets > > Abstract: z/OS 1.8 DFSMS provides page data set support which is not > exploited by z/OS 1.8 > > A page space is a system data set that contains pages of virtual > storage. The pages are stored into and retrieved from the page space by > the auxiliary storage manager (ASM). A page space is an entry-sequenced > cluster which is preformatted (unlike other data sets) and is contained > on a single volume. > > In z/OS 1.8 DFSMS provided support to allow a page space to have a > maximum size equal to 16,777,215 slots. The support in z/OS has not been > provided to allow a local page data set to be greater than 1,048,576 > slots. Though installations may define a page space larger than > 1,048,576 slots the additional space will not be used by z/OS. > Installations need to ensure they provide sufficient local page space > which is addressable by z/OS. > > The z/OS restriction of 4GB of page space applies to all page data sets; > PLPA, COMMON, and LOCALs. > > > Best Regards, > > Sam Knutson, GEICO > Performance and Availability Management > mailto:[EMAIL PROTECTED] > (office) 301.986.3574 > > "Think big, act bold, start simple, grow fast..." > > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On > Behalf Of Rob Schramm > Sent: Monday, March 03, 2008 9:45 AM > To: [email protected] > Subject: Re: Large Page Datasets APAR OA20749 > > Sam, > > I am curious about the unintended affect of OA20749. Do you know if it > "in general" remove the restriction of non-SMS VSAM being limited to > 4GB? > Definitively, Sam is correct. OA20749 simply provides ASM and Standalone Dump support for larger-the-4GB page data sets. Jim Mulder z/OS System Test IBM Corp. Poughkeepsie, NY ---------------------------------------------------------------------- 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
