At the risk of repeating myself, from the archives: http://bama.ua.edu/cgi-bin/wa?A2=ind0604&L=ibm-main&P=R6444&I=1&X=60035737B3F62727F2&Y=d10jhm1%40us.ibm.com
Date: Tue, 4 Apr 2006 00:56:20 -0400 Reply-To: IBM Mainframe Discussion List <IBM-MAIN@BAMA.UA.EDU> Sender: IBM Mainframe Discussion List <IBM-MAIN@BAMA.UA.EDU> From: Jim Mulder <[EMAIL PROTECTED]> Subject: Re: Support for MVS/SP 3.2.2 on zSeries??? In-Reply-To: <[EMAIL PROTECTED]> Content-Type: text/plain; charset="US-ASCII" IBM Mainframe Discussion List <IBM-MAIN@BAMA.UA.EDU> wrote on 04/03/2006 10:02:11 PM: > IIRC a z890 will only run a OS in 64-bit mode, no 31-bit mode, in an > LPAR. It may be possible to run a non-64-bit OS under z/VM. > > > > B Sysprog wrote: > > Hello - > > > > I have been asked to identify if it is possible to run an old,old version > > of MVS/SP and DFP (3.2) on a zSeries processor (z890). (this is not an > > April fool joke) > > > > Putting aside the issue of lack of support for such an old release, I > > seem to recall that > > nothing older than OS/390 R10 will run on zSeries. > > > > Anybody have any positive comments on this? > > Is there a way to run MVS/SP under some supported version of VM on zSeries? > > > > I have found a few hits on old releases of MVS in the archives from 1995 > > and 2000, > > but nothing specifically addressing this scenario. A z890 is quite capable of running ESA/390 mode LPARs. In fact, every IPL starts out in ESA/390 mode, and then the operating system does a SIGP SARCH into z/Architecture mode if desired. z890, z990, and z9 machines have a 2-level TLB. Nothing lower than OS/390 2.10 will run reliably on a machine with a 2-level TLB because lower releases than 2.10 do not do some of the necessary TLB purges. I have heard some speculation that you might be able to get around this by running an older MVS under VM, with the following VM trace: #CP TRACE IPTE RUN NOTERM Of course, this would cause some performance degradation, since VM would intercepting and simulating every IPTE for this virtual machine. I don't know of anyone who has tried this. It was just some hall talk with a VM developer. There may be other issues that would prevent an older MVS from running on a modern machine, such as missing support for a larger storage increment size. The storage increment size might also be avoided under VM if the virtual machine does not have too much real storage defined - I think VM simulates the increment size but I wouldn't swear to that. And there may be other issues that I am not remembering. The bottom line is that you won't find anyone who knows for sure. The only way you could find out is to try it. And as others have pointed out, if by "old, old" you mean pre-MVS/XA, you can most definitely forget that. Support for pre-XA architecture was dropped by the 9672 G4 machines (9672-Rx5). Jim Mulder z/OS System Test IBM Corp. Poughkeepsie, NY ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
