In z/VM, from the first release on, CPLOAD contained two CP nuclei: CPLOAD32 and CPLOAD64. During IPL, the 64 bit version was be loaded if the HW was capable, otherwise CPLOAD32 was activated. So indeed: if you used the standards, simply switching to a z-machine caused a switch from CP nucleus.
With z/VM V5, this bimodal CP went away; CPLOAD now is the 64 bit nucleus. 2007/6/26, Tom Duerbusch <[EMAIL PROTECTED]>:
The point I was trying to make was that with z/VM 4.x, there are two different nucleus programs. One for 31 bit and the other for 64 bit. And if your hardware change, causes you to change to a different nucleus, you might have problems, hence, something to stick in the back of your mind. I went from MP/3000, z/VM 4.2, 31 bit directly to z/890, z/VM 5.1, 64 bit. I did the operating system change at box swap. Changing from 31 bit to 64 bit was something that I directly knew. However, I recall when the dual image release of z/VM 4.x became available, and was initially installed on 31 bit hardware, when the box swap came to 64 bit hardware, there were many problems and questions on this listserv, about what went wrong. There was nothing wrong, ONCE, they realized there was a different supervisor running. And there was discussions on how to set the box back to run the 31 bit image. Obviously, not a problem or consideration for anyone running z/VM 5.x. Tom Duerbusch THD Consulting >>> Jim Bohnsack <[EMAIL PROTECTED]> 6/25/2007 1:27 PM >>> Tom--That doesn't match what I remember from when we first got the z9. I think that we, initially, ran with the 31 bit nuc on the z9. We are running 4.4, now, with the 64 bit option. Until recently, I ran my 2nd level test 4.4 system using the 31 bit nuc under a 4.4 nuc running with the 64 bit nuc. Tom Duerbusch wrote: > One small item to consider... > > zVM 4.x was the dual image release. There are 2 different supervisors. = > A 31 bit and a 64 bit one. As you will be going to a z9, you are required = > to use the 64 bit one. No big deal. =20 > > Except if you have something that is depending on your old supervisor. =20 > A patch you applied.. > Chaining thru the control blocks.. > > The default on the z/890 was the 64 bit supervisor. > If for some reason, you were running the 31 bit supervisor on your z/890 = > (which you can select), your only option is the 64 bit supervisor on the = > z9. > > Again, no big deal. Just something to keep in back of your mind, after = > conversion. > > Tom Duerbusch > THD Consulting > > > > >>>> Jim Bohnsack <[EMAIL PROTECTED]> 6/25/2007 8:10 AM >>> >>>> > We've been running 4.4 on a z9 since we got the z9 in February. There=20 > are no problems at all. We'll switch over to 5.3 later in the summer = > or=20 > fall. > > Jim > > -- Jim Bohnsack Cornell University (607) 255-1760 [EMAIL PROTECTED]
-- Kris Buelens, IBM Belgium, VM customer support
