Mike Schwab wrote: >z13 has 31 bit mode. z14 IPLs in 64 bit mode and cannot run 31 bit >Operating systems, z/OS 2.2 SA-ICKDSF, etc. Requires z/OS 2.3 >SA-ICKDSF.
These points really aren't enough to know whether OS/390 2.5 will IPL and run on a z13 or z13s machine. "No" would be my educated guess. All they mean is that OS/390 2.5 definitely won't IPL in a LPAR on the z14. By the way, although z/VSE 4.1, 4.2, and 4.3 are out of support, IBM has disclosed that z/VSE 4.x is known to IPL (start up) under z/VM on the IBM z14. You have to use the CP command SET MACHINE ESA in z/VM to make that happen. Those releases of z/VSE are nominally ESA/390 (at IPL), but my understanding is that they flip to z/Architecture almost immediately since they have some z/Architecture exploitation (64-bit real addressing for certain system functions). Consequently SET MACH ESA seems to work for them, but trying to run any of those z/VSE releases in a LPAR on the z14 doesn't work. And SET MACH ESA doesn't seem to offer any help for any other operating systems that IPL in ESA/390 mode (or earlier modes). Anyway, that's the one ESA-related IPL footnote for the IBM z14, of possible interest in migration scenarios from z/VSE 4.x to the latest release of z/VSE. And the new z/VM sub-capacity licensing can be helpful here, too. We should also probably mention that OS/390 2.5 contains known (by now) security vulnerabilities, possibly integrity ones, too. Those vulnerabilities could be exploited when any other client or system connects, even if the OS/390 2.5 system is not "directly" connected. This sort of "leapfrogging" has certainly happened before, and unfortunately it's safe to say it'll happen again. However, I assume Mark at RSM is already extremely familiar with these significant and growing risks. I agree with Brian that there are some organizations (and people within them) that don't seem to make rational decisions. If this site happens to be within my part of the planet (a large part of it), perhaps I can help, but please contact me offline. -------------------------------------------------------------------------------------------------------- Timothy Sipples IT Architect Executive, Industry Solutions, IBM Z and LinuxONE, AP/GCG/MEA E-Mail: sipp...@sg.ibm.com ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
