I'm not advocating this practice. Just saying that we did it for 25 years without a failure. We're now moving to totally different technology where such action is not even in the picture.
. . J.O.Skip Robinson Southern California Edison Company Electric Dragon Team Paddler SHARE MVS Program Co-Manager 323-715-0595 Mobile 626-543-6132 Office ⇐=== NEW robin...@sce.com -----Original Message----- From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of R.S. Sent: Monday, May 25, 2020 5:53 AM To: IBM-MAIN@LISTSERV.UA.EDU Subject: (External):Re: Opinions/experience on sharing catalogs outside plex CAUTION EXTERNAL EMAIL Skip, In the past I implemented STK tapes, the largest tape system in Poland at the time. Interesting job. :-) It seems, you shared control datasets between datacenters. Assuming your second datacenter is for disaster recovery, you had single point of failure. Catalog is not important there, but availability of datasets is. How could you work with tapes in case the datasets are lost due to catastrophe of primary DC? IMHO the only way was to have remote copy of control datasets. Last, but not least, as far as I remember the datasets were very specific - they have (had?) hardcoded both volume labels and device numbers. While remote copy replicate volume label, the dev num is IODF dependend. There was a method for that, I forgot details. Other method could be a trick with duplicate device numbers. -- Radoslaw Skorupka Lodz, Poland W dniu 24.05.2020 o 21:29, Jesse 1 Robinson pisze: > Until recently, we shared a catalog not only across sysplexes but > between data centers. All because of tape. We had STK virtual tape (in > both data centers) supported by MIA (Multi Image Allocation). These > products require control data sets shared among all exploiting > systems. We could have managed with uncataloged data sets, but that > was deemed riskier in the long run than a shared catalog. The only > entries in the catalog were for tape management data sets. We never > had a catastrophe. 😉 > > . > . > J.O.Skip Robinson > Southern California Edison Company > Electric Dragon Team Paddler > SHARE MVS Program Co-Manager > 323-715-0595 Mobile > 626-543-6132 Office ⇐=== NEW > robin...@sce.com > > -----Original Message----- > From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of > R.S. > Sent: Monday, April 20, 2020 7:42 AM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: (External):Re: Opinions/experience on sharing catalogs > outside plex > > CAUTION EXTERNAL EMAIL > > Well, it is not good idea, but sometimes even such idea is better than > nothing. > What's important the risk covers THIS catalog only, not whole world. > > And yes, this catalog and shared datasets should be shared without "sysplex > features" like changes is serialization. RESERVE should be used here or > CA-MIM should be used, but the last one is add-on tool. > > BTW: BCS can be defined with SHR(3 4) or SHR(3 3). For this case it has to be > SHR(3 4). AFAIK it is alterable. > > Again: small activity is your friend here. Small number of datasets cataloged > in the BCS is good here. Potential problems with the BCS will not affect > other BCSes. > > I use it for years (with limited activity). Mostly PS files and some VSAM. No > problems observed. > Caution: PDSE *will* break despite of way how catalog is shared. No help from > CA-MIM, AFAIK. Observed many times educated many guys who used PDSE for > sharing. > > -- > Radoslaw Skorupka > Lodz, Poland > > > > > > > W dniu 20.04.2020 o 14:45, Allan Staller pisze: >> Yes, it can be done. I reiterate, IMO, this is most likely not a good idea. >> In order to accomplish this safely, you also need to regress GRS to pre-GRS >> functionality. >> Everything affecting this catalog must be handled w/Reserve/Release, >> and not normal processing VSAM Sharoptions for the catalog need to be >> changed. IIRC when I "undid" this the catalog hand Shareoptions (2,3) (or >> was it 4,3?). >> This option tells z/OS that the user is responsible for Catalog >> seriailization. >> SYSDSN, SYSIGGV2, SYSVTOC, SYSZVSAM (?) and the SPF* queues need to be >> excluded from GRS processing. >> >> In my case that led to various deadly embraces that usually led to manual >> intervention. >> >> My $0.02 USD on this is: Why point the shotgun at your foot? >> >> -----Original Message----- >> From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On Behalf Of >> R.S. >> Sent: Monday, April 20, 2020 3:45 AM >> To: IBM-MAIN@LISTSERV.UA.EDU >> Subject: Re: Opinions/experience on sharing catalogs outside plex >> >> [CAUTION: This Email is from outside the Organization. Do not click >> links or open attachments unless you trust the sender.] >> >> W dniu 09.04.2020 o 02:11, Rob Schramm pisze: >>> I am considering sharing some usercats outside of a sysplex. What I >>> can find is that sysiggv2 must be kept as a reserve to do so. >>> >>> Looking for others that have had to do this. >>> >>> One question I had was, what happens on a ispf 3.4 when the data set >>> is part of the catalog but exists in another system? Ief238d? >> My €0.02 >> >> 1. You can share catalogs between sysplexes. Note: we mean BCS, which is >> usually called catalog. >> 2. The less activity on the BCS the better. >> 3. The above means: >> 3.1. Avoid keeping non-shared datasets in the BCS. Use another BCS for that. >> 3.2. It is not bad idea to have multiple "small" shared BCSes. >> 4. You cannot use any sophisticated catalog sharing features like RLS or ECS. >> >> Regarding you last question: I understand it as you have entry in the BCS, >> but the dataset reside on volume which is not share, that mean it is >> unavailable for one system. It's nothing exotic. It's like orphan catalog >> entry, which sometimes may happen even without BCS sharing (usually as >> result of human error). >> However that also means the sharing is not done correctly. The best scenario >> is when all datasets cataloged in shared BCS reside on volumes which are >> also shared. Preferably the BCS is also on the volume from that group. >> Keep it simple. >> >> -- >> Radoslaw Skorupka >> Lodz, Poland ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
