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]

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