On Friday, 01/30/2009 at 03:05 EST, Tom Duerbusch <[email protected]> wrote: > The only exposure is at VM IPL time. > > You can have duplicate VM system volumes all you want. It is only a problem at > VM IPL time. > > If you have multiple LPARs, you can have duplicate volumes, just code the IOCP > to allow only one set of VM volumes to each LPAR.
It would be better if you used OFFLINE/ONLINE_AT_IPL in SYSTEM CONFIG and have different CONFIG files if needed; one pointing at primary volumes, another at secondary/backups, another at Golden IBM Masters (your recovery system!), and so on. They can always be brought online manually later as needed. No accidental formatting. No accidental attachment to SYSTEM at IPL. No worries about IOCP changes (well, fewer worries). Corollary: management doesn't need to keep a rolled-up newspaper at the ready and no need to yell "Bad, Sysprog, Bad! Shame on you! Look at the mess you made!" :-) Alan Altmark z/VM Development IBM Endicott
