On Thu, 10 Nov 2005 09:54:26 -0500, Clark, Kevin D, HRC-Alexandria/EDS
<[EMAIL PROTECTED]> wrote:
>Question:
>
>I have a few lpars with 192MB of real defined. Would that be enough for
>64-bit testing ?
>
The absolute minimums are documented in the Planning for Installation
manual (see cut/paste from section 4.3.1.2 - z/OS 1.4 below).
<my 2 cents>
As far as 64-bit bugs with more than 2G real, as Chris pointed out
the IBM bugs have been fixed for years. So have the ISV bugs. So
unless you are running very old ISV software, I personally wouldn't
give it a second thought.
As far as Skip's points about in-house programs that may fail, he
is on target, but I haven't seen this to be an issue in any of the
conversions I was personally involved in - and while consulting
I was involved in lots of them at many different shops (perhaps he
and others have though). I ran into one 64-bit problem at one client
with an IBM tool for monitoring LLA (MFM - Module Fetch Monitor)
and Peter Relson fixed that in 2002.
Even if you have a surplus of memory and can add enough to a test
environment so there is more than 2G real, can you identify and
test every home grown program in the shop? Is it worth the trouble
even if you could?
At this point I would take a leap of faith and just make sure you
have a backout plan. As long as you are current on maintenance,
I highly doubt you'll be backing out due to a 64-bit issue. If your
conversion to 64-bit is coupled with an OS upgrade at the same time,
it is much more likely you'll have issues realted to that.
</my 2 cents>
Here is the doc from the z/OS 1.4 planning for installation on the
minimum processor storage required to IPL:
4.3.1.2 Processor storage
Expanded storage is not supported in z/Architecture. Thus, you must
configure your LPAR to use only central storage (and not expanded
storage).
The minimum processor storage required to IPL z/OS or z/OS.e depends on a
number of factors, including the number of devices in the I/O
configuration, the amount of storage configured, the number of address
spaces created, the types of applications supported, and the products
and subsystems supported in the IPLed system. Nevertheless, we can make the
following statements about the minimum processor storage
required to IPL:
It does not usually change from OS/390 release to OS/390 release, z/OS
release to z/OS release, or z/OS.e release to z/OS.e release.
It increases when you make the jump from OS/390 to z/OS or z/OS.e. This
is due to the change in architecture (from 31-bit ESA/390
architecture to 64-bit z/Architecture) when you run z/OS on a z800 or
z900 server, or z/OS.e on a z800 server.
It should be the same for z/OS.e as for z/OS.
In IPL studies at IBM, 24 MB were required to IPL the last three OS/390
releases (R8, R9, and R10). Also in the studies, 35 MB were required to IPL
the first two z/OS releases (V1R1 and V1R2). The systems in the studies
were IPLed to the point of completing JES initialization. The systems had
I/O configurations defined with the following devices:
Device Quantity
3270 32
3390 1152
3490 16
In additional studies with different I/O devices, 42 MB were required to
IPL z/OS V1R3 and z/OS V1R4. The systems in the studies were IPLed to
the point of completing JES initialization. The systems had I/O
configurations defined with the following devices:
Device Quantity
3270 32
3390 3264
3490 16
OSA 32
Cheers,
Mark
--
Mark Zelden
Sr. Software and Systems Architect - z/OS Team Lead
Zurich North America and Farmers Insurance Group
mailto: [EMAIL PROTECTED]
Systems Programming expert at http://Search390.com/ateExperts/
Mark's MVS Utilities: http://home.flash.net/~mzelden/mvsutil.html
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