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 [email protected] -----Original Message----- From: IBM Mainframe Discussion List <[email protected]> On Behalf Of R.S. Sent: Monday, April 20, 2020 7:42 AM To: [email protected] 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 <[email protected]> On Behalf Of > R.S. > Sent: Monday, April 20, 2020 3:45 AM > To: [email protected] > 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 [email protected] with the message: INFO IBM-MAIN
