Mary Anne,
I'd call it a "Best Practice" to reserve cylinder zero for the actual disk label and the CP allocation bit map, but it is not required. If your existing volume already has Linux data on cylinder zero it's not worth moving it, but it's sound advice for future minidisks.
You might find it useful to review the MDISK statement description in Chapter 17 of the "z/VM CP Planning and Administration" manual. To add the real DASD as a minidisk for LINUX1's use:
Xedit USER DIRECT, locate the LINUX1 directory entry with command: /R LINUX1
Then insert the minidisk statement similar to:
MDISK vdev 3390 1 10016 volser M readpw writepw {this keep cylinder zero away from the guest}
or
MDISK vdev 3390 0 10017 volser M readpw writepw {this allows the guest to access the whole volume, including cylinder zero)
Where:
vdev = the minidisk address, maybe you want it different from the real DASD address as a reminder.
For this example, let's use: 0391
If you choose to change the address, make appropriate changes to Linux statements, too.
volser = the volser of the real disk at 1A0
readpw = a password used by any other VM user to CP LINK that disk in R/O mode
writepw = a password used by any other VM user to CP LINK that disk in R/W mode
Then:
FILE (TSO's: SAVE;END) the updated USER DIRECT
run: DIRECTXA USER DIRECT *
At that point you DETACH the disk, from LINUX1 enter:
unmount 1A0 (using the appropriate Linux unmount command)
#CP DET 1A0
then from OPERATOR or MAINT, enter:
#CP ATT 1A0 SYSTEM
Either logoff and logon LINUX1, or from LINUX1, enter: CP LINK * 301 301 {by default, as entered in the CP directory, you LINUX1 will get the disk R/W unless someone else has it R/W).
Each time LINUX1 logs on the MDISK statement will attempt to gain access to that minidisk in R/W mode.
In a previous post you mentioned use of the CP command" DEFINE MDISK
IMHO opinion that (very powerful and important) command is really just meant as an "oops/recovery" command for when you (a sysprog, not a mere mortal) need to access a minidisk but can't reach it via a LINK command for one reason or
another. That 'one reason or another' is, in my experience, been when you are accessing minidisks defined on another VM system, but not on yours (perhaps a second level VM system), or for when the CP directory is not available for some reason (usually just after you shot yourself in the foot). :-)
Mike Walter
Hewitt Associates
The opinions expressed herein are mine alone, not my employer's.
| "Mary Anne Link"
<[EMAIL PROTECTED]>
Sent by: "The IBM z/VM Operating System" <[email protected]> 06/29/2006 12:37 PM
|
|
Hi Jim, thanks for your help. I tried your command and got:
HCPLNM107e Linux1 0A10 not linked, not in CP directory
At that point I had 0A10 attached to Linux1. I detached it and attached i
t
to system and got the same message.
I thought about defining the mdisk to maint and then trying to link to it
...
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