I'd say the recovery userid you specify will be ignored. In fact, in such a "single user GCS" userid you could run RSCS, VTAM, VSCS, and AVS together, they are all multitasking. An abend in one would cause the death of them all. That's -I guess- why the help mentions "test environment". The GCS recovery machine is mainly meant to be able to cleanup the common storage gotten by a member when that dies. E.g. when VTAM starts, it tells the recovery machine to run program ITSxxxx when it would die, it would FREEMAIN the storage gotten by VTAM. In a "single user GCS" system there is no such problem of common storage that must be freed in case of abend.
2009/4/21 Schuh, Richard <[email protected]> > Rather than GROUP=NO, there is an entry for "Single User Environment (YES > or NO)". Above that line, there is one that asks for "RECOVERY MACHINE > USERID (required)" > > The note dealing with the single user entry reads: > > > 5. Will the GCS system run in a single user environment? > > Enter YES to create a single user environment. Specify NO, to create a > > group environment with common shared storage. > > Applications that do not require group communications and that run > > without the use of shared common storage can run in a single system > > environment. These applications will run without the overhead of group > > initialization and multiple virtual machines. For example, a test > > environment requiring a single user and not group communications will > > be able to run without the overhead of group initialization and the > > multiple virtual machines. > > > > I take that, "the multiple virtual machines," in the last two statements to > mean other machines like VTAM, ACS and buddies, but does not include the > recovery machine (which is, per the display, required). The note related to > the recovery machine question states that the GROUP command does check the > recovery machine userid for validity, "but does not prevent you from saving > an incorrect entry." What does that mean? You can put in something that > would be acceptable as a userid, even though there is no such id in the > directory, or it must be an existing id, even including one that is NOLOG? > > All of that begs the question, how do you accomplish running without the > recovery machine? Do you simply enter an id and never log it on? I know that > in multiple user mode, GCS refuses to come up in RSCS or any other machine > in the group if the recovery machine is not already on. The documentation is > perfectly clear (to the one who wrote it). > > > > Regards, > Richard Schuh > > > > > ------------------------------ > *From:* The IBM z/VM Operating System [mailto:[email protected]] *On > Behalf Of *Kris Buelens > *Sent:* Tuesday, April 21, 2009 12:03 PM > > *To:* [email protected] > *Subject:* Re: Question on SERVICE EXEC and PUT2PROD > > You need to build a special GCS for it. Try this in MAINT > VMFSETUP ZVM GCS > GROUP > or maybe GROUP GCSRSCS > Group presents panels to define GCS > > 2009/4/21 Schuh, Richard <[email protected]> > >> Where is this discussed? When I search the books on the RSCS shelf for >> GROUP=NO, all I get is a blank page. Neither do I get any hits when >> searching the "z/VM Group Control System" manual. >> >> Regards, >> Richard Schuh >> >> >> >> > -----Original Message----- >> > From: The IBM z/VM Operating System >> > [mailto:[email protected]] On Behalf Of Alan Altmark >> > Sent: Tuesday, April 21, 2009 10:30 AM >> > To: [email protected] >> > Subject: Re: Question on SERVICE EXEC and PUT2PROD >> > >> > On Tuesday, 04/21/2009 at 01:21 EDT, Kris Buelens >> > <[email protected]> >> > wrote: >> > > For GCS, even SERVICE is a bit disruptive: the GCS saves system is >> > replaced, >> > > what means an IPL GCS will fail untill the GCS recovery >> > machine (hence >> > all >> > > other GCS users) are restarted. Q NSS USERS GCS will >> > reveal which of >> > your >> > > users might be affected. Without SNA, RSCS is probably the >> > only user. >> > >> > For non-SNA networks, I prefer to run RSCS in single-user >> > (GROUP=NO) mode so that there is no recovery machine and it >> > can be treated like a stand-alone CMS user. >> > >> > Alan Altmark >> > z/VM Development >> > IBM Endicott >> > > > > > > -- > Kris Buelens, > IBM Belgium, VM customer support > > -- Kris Buelens, IBM Belgium, VM customer support
