This is a USER cat procedure https://www.ibm.com/docs/en/zos/2.5.0?topic=catalog-reorganizing-changing-size-bcs .
I am sure you need more steps like attaching as user catalog on another system, and ALIAS definitions. On Fri, Nov 21, 2025 at 7:50 AM Colin Paice < [email protected]> wrote: > How do you rebuild a catalog - copy it to a different catalog, or extract > everything , create "define alias.." statement and process those > statements through IDCAMS? > > Colin > > On Fri, 21 Nov 2025 at 05:55, Brian Westerman < > [email protected]> wrote: > > > It keeps the Master Catalog clean, and makes sure that any catalog > > maintenance changes that may have occurred between the versions (not the > > minor releases) will be used to generate the new Master Catalog. It also > > forces a re-think on what is and needs to be "in" the Master Catalog. > > > > I'm not the only one that can put things into the Master at any of the > > sites I work with, there are people at the actual site who can update the > > Master who normally don't really think about whether something needs to > be > > there or not. Lots of things change between the time z/OS version 1 came > > out and then version 2 now version 3. There have been many changes > between > > those releases that have benefited the Master Catalog (and catalog in > > general). Keeping the same Master for 10 to 20 to 30 years, to me seems > > like asking for trouble. And yet, there are sites that brag about having > > the same Master Catalog and Usercats from when they started xx years ago. > > I think they are probably thinking something along the lines of, "they > > still work, why change anything?". > > > > There is a lot of obsolete stuff in there at almost every site I have > been > > exposed to. The entire rebuild process takes maybe 15 minutes and I end > up > > with a pristine Catalog structure. I generally rebuild the User Catalogs > > as well, but mostly so I can move them where they "should" be for > recovery > > purposes. > > > > The question you asked maybe should have been to ask yourself, "what are > > you losing by not rebuilding the Master Catalog"? I realize that people > > have probably some very strong feelings on this one way or the other, and > > that's their privilege. I believe that occasionally rebuilding the > Master > > (and the user catalogs) can be beneficial, and when it's been a "log > time", > > I know it is. Personally I think that some sites don't do it because > they > > aren't really that confident in their skills, but the perfect time to > > rebuild (and reallocate), is when you generated the new system. There > > isn't much that can go wrong anyway, but at installation time you have > the > > time to think about EVERYTHING in a lot more detail, at least you should. > > > > I probably do more installs of the whole system and all of it's > subsystems > > than a "normal" (normal is probably not the correct word here) systems > > programmer, and I have a extremely long "to do" list of the process > (almost > > 3,000 steps depending on the subsystems and vendor products involved). I > > have seen countless Master Catalog issues that people just "live" with > > because they don't see a benefit in fixing it. In my case, I don't even > > bother to take the chance that I will prolong a problem. > > > > In this case, the choice is up to the person who is doing the install. > If > > that's me, then of course "my way" will be the right way no matter what > > anyone else thinks. I have yet to have even one site complain about me > > recreating the Catalog(s), and that's a lot of sites. > > > > Brian > > > > ---------------------------------------------------------------------- > > 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 > -- Mike A Schwab, Springfield IL USA Where do Forest Rangers go to get away from it all? ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
