Radoslaw, I have looked in a lot of places for the differences between version 1 and version 2 Extended format data sets. I have asked questions of IBM and not got answers. The only place I have found anything is in the description of the EXTPREF parameter of DSNTYPE in the JCL reference manual. It explains how behaviour may be different, but not any details of the underlying changes. I suspect that is information only available to those who fully understand the contents and role of those extra 32 bytes on each physical block.
Lennie Dymoke-Bradshaw Consultant working on contract for BMC mainframe Services by RSM Partners ‘Dance like no one is watching. Encrypt like everyone is.’ -----Original Message----- From: IBM Mainframe Discussion List <[email protected]> On Behalf Of Radoslaw Skorupka Sent: 03 April 2021 23:04 To: [email protected] Subject: Re: Stand Alone Dump questions Jim, It is not related to SADUMP, but definitely related to z/OS: You mentioned extended format PS is restricted to ~4Gi blocks per volume. Where is it documented? This is information I'm trying to find and sometimes I see some clues, but no reference to the documentation. Another question: what about "format 2" of ext-fmt PS? Is there any documentation or presentation clarifying the differences? BTW: I know there is limitation for EAV, which is currently approx. 1TB, so ext fmt block count limitations is rather too big. -- Radoslaw Skorupka (looking for new job) Lodz, Poland W dniu 01.04.2021 o 18:15, Jim Mulder pisze: > As stated in the manual: > > Do not place a data set that is intended to contain a > stand-alone dump on a volume that also contains a page > data set that the stand-alone dump program you might > need to dump. When stand-alone dump initializes a page > volume for virtual dump processing, it checks to see > if the output dump data set also exists on this volume. > If it does, the stand-alone dump program issues > message AMD100I and does not retrieve any data from > page data sets on this volume. Thus, the dump might > not contain all of the data that you requested. > This lack of data can impair subsequent diagnosis. > > The dump data set cannot be defined on the same > volume that contains the IPL text of stand-alone dump. > > The maximum size of a single-volume DASD dump data > set depends on the type of data set. > > Conventional sequential (DSNTYPE=BASIC) data > sets can span 65,535 tracks per volume, and can > hold approximately 3 GB per volume. > > Extended format (DSNTYPE=EXTREQ) data sets are > supported by z/OS® V1R6 and later releases. Extended > format sequential data can hold 4,294,967,295 blocks > per volume. The maximum size for extended format > sequential is approximately 98,304 GB per volume. > You cannot use striping or compression options for > extended format sequential data sets. You must use > the guaranteed free space option to require DFSMS > to reserve space at the time that the data set > is created. > > Large format data sets are supported by > z/OS V1R7 and later releases. Large format > (DSNTYPE=LARGE) data sets can span 16,777,215 > tracks per volume. The maximum size for large > format data sets is 768 GB per volume. > > > Jim Mulder z/OS Diagnosis, Design, Development, Test IBM Corp. > Poughkeepsie NY > > "IBM Mainframe Discussion List" <[email protected]> wrote on > 04/01/2021 10:12:52 AM: > >> From: "Richards, Robert B. (CTR)" <000001c91f408b9e-dmarc- >> [email protected]> >> To: [email protected] >> Date: 04/01/2021 12:05 PM >> Subject: Stand Alone Dump questions >> Sent by: "IBM Mainframe Discussion List" <[email protected]> >> >> It has been a long time since I messed around with modifying this >> stuff and, yes, I should RTFM, but I'm asking here so others can >> benefit from the questions (that's my story and I'm sticking with it!@ > <grin>) >> Is there any reason *not* to use Mod-27 or -54s volumes? >> >> Is there any reason against placing the SADMP text on the first of >> the SA dump volumes? >> >> Are there any size restrictions on the datasets? >> >> Thanks for any and all answers, >> > > > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
