The last sentence of the requirement reads, "I believe IBM needs a new approach to the handling of these situations. Either there needs to be a formally agreed process for having 2 or more master catalogs in a sysplex, or there needs to be a way for VSAM data sets to be “multiply-owned” by more than one catalog."
I think this includes a "dual MCAT solution". Lennie -----Original Message----- From: IBM Mainframe Discussion List <[email protected]> On Behalf Of Radoslaw Skorupka Sent: 29 November 2023 18:32 To: [email protected] Subject: Re: Page Datasets in User Catalog Lennie, I won't support it, because I don't want it. In my opinion it is bad approach. BTW: there is quite new feature F CATALOG,RESTART(new.mcat.dsn) which I like. As an alternative I would consider some solution like dual MCAT - similar to dual RACF db, or Db2 log. -- Radoslaw Skorupka Lodz, Poland W dniu 29.11.2023 o 19:27, Lennie Dymoke-Bradshaw pisze: > Radoslaw and others, > Please consider supporting my idea on the ideas portal. > > Better support for multiple master catalogs in a sysplex. > https://ibm-z-hardware-and-operating-systems.ideas.ibm.com/ideas/ZOS-I-3890 > > Lennie Dymoke-Bradshaw > https: //rsclweb.com > -----Original Message----- > From: IBM Mainframe Discussion List<[email protected]> On Behalf Of > Radoslaw Skorupka > Sent: 29 November 2023 15:42 > To:[email protected] > Subject: Re: Page Datasets in User Catalog > > W dniu 29.11.2023 o 04:56, Mark Zelden pisze: >> On Thu, 23 Nov 2023 14:20:51 -0600, Jon Perryman<[email protected]> >> wrote: >> >>> On Wed, 22 Nov 2023 22:35:13 +0000, Seymour J Metz<[email protected]> wrote: >>> >>>> I suspect that there was a game of telegraph, whereby crucial details got >>>> lost. >>>> >>>> It is normal to allocate page datasets in a user catalog that will >>>> eventually be used as a master catalog. >>>> I'm suspicious of the claim that z/OS can use a page dataset that is not >>>> in its own master catalog, but I can't rule it out. >>> There are definitely crucial details lost. Page and swap are special >>> datasets. For instance, a page dataset can be in multiple catalogs (I think >>> using recatalog). >> Pagespace can be in multiple catalogs (which should be a master to the >> system that is using it) via RECATALOG. I think at one time it had to >> have a HLQ of PAGE or SYS1 but my memory is fuzzy on that part. I know for >> a long time the HLQ doesn't matter at all for pagespace and it could still >> be in >> multiple catalogs. This also applies to swapspace and VSAM linear ZFS that >> is indirectly cataloged. >> Any SYS1 VSAM dataset can be in multiple catalogs via recatalog. >> >> Don't ask me where this is documented now. :) I'm guessing "DFSMS managing >> catalogs". > > I dare to correct the above considerations. > 1. Any non-VSAM and non-SMS dataset can be catalogued twice or multiple > times. Reason is obvious: there is no backward reference. It is just entry in > BCS, which contains DSN, UNIT and VOLSER. > 2. VSAM datasets *cannot* be catalogued multiple times. And there is a way to > enforce it - VVDS. > 3. IBM created exceptions for the 2. but only for SYS1 and PAGE HLQ. > Note - this is matter or HLQ, not VSAM type or flavour. In other words one > can "multi-catalog" any SYS1.VSAM.DSN regardless of its purpose and any > PAGE.VSAM.DSN, also regardless of its purpose. > 4. Page dataset is specific kind of VSAM, because it is somehow formatted > before use. As one may know DEF PAGE takes significantly more time than > regular DEF CL and depends on its size. > 5. So, it is still possible to have good reason to create some page datasets, > even cataloged in UCAT, but for future use. And future use will require page > datasets to be in MCAT. How? a) recatalog. b) my current UCAT is de facto > other system's MCAT. Other scenarios may apply. > > > My €0.02 > > -- > Radoslaw Skorupka > Lodz, Poland > ---------------------------------------------------------------------- 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
