On Tuesday, 07/18/2006 at 11:08 MST, Mike Lee <[EMAIL PROTECTED]> wrote: > The 3.1 manual was quoted since it goes back even further than a 4.3 manual.
:-) But is never "correct" for a later release of VM. > I thought that since V-DISK in a 4.3 system can be 4194296, I erroneanously > thought that that value would be this MAXFBA value instead of 1672881. > Actually, having never run into this limitation before with VM FBA disks > on P390 and FLEX systems I had always assumed that one could make > them any size as long as the underlying opsys (z/Vse) could handle them > until seeing this table of limitations. Yes, it's easy to fall into the trap of assuming that CP will handle whatever geometry and capacity devices you give to him. He won't. Of course, hitting those limits is really a rare event. The problem in the book has been there nigh on forever (as measured from the CPU's perspective) and no one tripped over it until now. Lucky you! ;-) And this isn't the first time that a guest could support something the underlying CP could not. Of course, putting a newer guest on an older CP isn't really a fair comparison! They need to be of the same vintage for a grapes-to-grapes comparison. > So I have for the first time, z/VSE can support a larger FBA disk than > z/VM 4.3. Solutions are to upgrade to z/VM 5.1 or try to patch > z/VM 4.3 with patching appearing to be a quick short term solution. > I can find and zap the four occurrences of the full word containing > 1672881 in the DIRECTXA MODULE without locating any source > and a method to properly assemble and link it. However, I need another > clue for HCPIDT. Actually, I don't think I would bother. Upon closer inspection, it may not be HCPIDT in z/VM 4.4. z/VM 5.1 is the only really viable path unless you have access to the z/VM 4.4 CP source code and want to wade through it. Blindly changing 1672881s to something else is not really a good idea. You have no idea whether you are changing the FBA limit, two adjacent halfwords that happen to have that value, an unrelated constant, or part of the instruction stream. Alan Altmark z/VM Development IBM Endicott
