I always keep the virtual address different from the real address.
(unless I'm running in a perferred guest system)

RE:  That allows me to easily move minidisks to other units without
making any other changes then the "user direct" file.  Also, if you have
multiple minidisks defined on a real volume, which minidisk gets the
real address.

Note, I do use real addresses for the $alloc$ and $endpak$ ($endpak$
locates the last cylinder on a pack so diskmap can show end of pack,
gaps....my modification).

Yes, I do use basically the same virtual addresses for disk in each of
my Linux machines.  Not that Linux cares that much about addresses since
Linux uses "devices" instead.  But cloning is easier.  Documentation is
easier (150 is the root, 151 is /usr, 293 is swap, etc), and, so far,
the only problems this has caused in the last 20 years (VSE and Linux
guests), saved me from more problems as people that "though" they knew
what they were doing, tried to make changes.  When virtual = real
addresses, they would have had sufficient info to really screw things
up.  When the virtual address didn't match anything, it stopped them and
they gave me a call and stopped them from really messing things up.

Tom Duerbusch
THD Consulting

>>> [EMAIL PROTECTED] 06/10 9:13 AM >>>
I have a general administration / setup question for people who are
running
multiple Linux/390 systems under z/VM. Do all your Linux instances use
the
same virtual addresses for things like DASD, regardless of the actual
device
address? Or do you find it "better" to make the virtual DASD address
match
the actual device address? I'm tending towards making all Linux/390
instances use the same set of virtual DASD addresses, which are not
even
related to the "real" DASD addresses. I think this would be easier to
maintain and "clone" new instances. Do you even try to make the Linux
DASD
addresses "look like" the actual device numbers, or do you simply have
a
range of virtual DASD addresses that you assign to physical devices.
I'm
using MDISK statements for Linux DASD. Basically, so far, I give each
instance (OK, I only have one so far), the entire device OTHER THAN
the
first cylinder. Sorry, but I don't trust the Linux administrator to
not
destroy the DASD label, so this protects it from any mistakes. Oh, I'm
the
OS/390 and z/VM (new) sysprog. I am familar with Linux on Intel and did
help
the Linux administrator set up the initial Linux/390 system because she
is
not s390 literate. And I had actually done a SuSE s390 install at home
under
Hercules/390. So I was the "expert".


--
John McKown
Senior Systems Programmer
UICI Insurance Center
Applications & Solutions Team
+1.817.255.3225

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