Thanks Scott for the definitive answer, it does clear up a lot. Like I mentioned, it's not a game breaker really. I can't come up with a situation where this behavior would lock us out of our machine. Unless we really dropped the ball somewhere in the first place. It's more that the list might be interested to know.
_Jan -----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Scott Ballentine Sent: woensdag 26 augustus 2015 6:13 To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: vary <dev>,console with an IEF238D outstanding. > While there is an IEF238D outstanding, in our case because some DD specified > a nonexistent volser, "vary <dev>,console" gives us IEE799D. > > <quote> > IEE799D VARY CONSOLE DELAYED - REPLY RETRY OR CANCEL. > > A VARY CONSOLE command requested that a console be placed online or offline. > The system could not process the command due to other processing in > the system such as: > - Another VARY CONSOLE command > - Device allocation in progress > </quote> I'd expect that. As a general rule, when IEF238D is outstanding, it holds various resources. SYSIEFSD Q4 shared is one of those resources, but there are several others. Device Allocation requires a consistent picture of the online devices, serialized by Q4. There are a lot of processes that can be held up if an IEF238D is outstanding. Over the years, we've tweaked some things to help with Q4 contention, but the general rules for serializing devices with Q4 I describe here have always been true. For most devices, you can VARY them online while IEF238D is outstanding, but not offline. (We only need Q4 shared to make a device eligible for allocation, but to take a device away from allocation, we need Q4 exclusive.) Offline devices will go into a pending offline state until Q4 becomes available. For console devices (I mean those in CONSOLxx, not just 3270's in general) are special. Moving them into console state requires Q4 exclusive, because you're taking the device away from allocation (it's no longer allocatable.) The "console state" is separate from online or offline. Sorry, that serialization is really necessary. -Scott Ballentine IBM z/OS Device Allocation ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
