On Wednesday, 09/02/2009 at 04:24 EDT, Adam Thornton <athorn...@sinenomine.net> wrote: > On Sep 2, 2009, at 3:13 PM, Schuh, Richard wrote: > > > I think it goes more to separating production from installation/ > > maintenance. It the volsers are different, changing something on the > > system must be deliberate. Accidental update is very difficult. Alan > > is big on data integrity, well ... as big as he can be. > > But....unless you're installing your second-level systems on dedicated > devices, would you ever have duplicate volsers? And, uh, why would > you install second-level like that unless you really, really meant it?
Richard has the right of it. Within the domain of "all online dasd" you have a system and data integrity obligation to ensure that CP does not use the wrong dasd volumes at IPL time. Rule #48: Never have duplicate volids "online" during IPL. Period. No exceptions. If you have a set of backup system volumes with the same labels, make sure each has a SYSTEM CONFIG that has the "other" set of system volumes OFFLINE_AT_IPL. If you have "alien" volumes in your LPAR, make sure they, too, are OFFLINE_AT_IPL. Personally, I like OFFLINE_AT_IPL 0000-FFFF and then ONLINE_AT_IPL only those represented within SYSTEM CONFIG. Bring the remainder online in AUTOLOG1 before you start bringing up guests with dedicated dasd or DEVNO minidisks. Alan Altmark z/VM Development IBM Endicott
