Steve,
Just a suggestion, check the storage itself to make sure that the
volumes are not set to r/o.
I've been plagued with read-only situations due to a myriad of
reasons but the 'write protected' reminds me of the one situation where
the storage itself were set to read-only as they were DR volumes.
Thanx,
Joe Comitini
TD Ameritrade - Senior SystemZ Engineer
Office: (201) 369 - 8436
Cell: (551) 200 - 7781
From: The IBM z/VM Operating System [mailto:IBMVM@LISTSERV.UARK.EDU] On
Behalf Of Perez, Steve S
Sent: Tuesday, March 01, 2011 6:00 PM
To: IBMVM@LISTSERV.UARK.EDU
Subject: Re: zLinux OS disk read-only
When my zLinux Admin issued this command in the zLinux guest machine, he
got the write-protected message indicating to him that the OS disk is
read-only...
# mount -o remount,rw /dev/VolGroup01/LogVol00
mount: block device /dev/VolGroup01/LogVol00 is write-protected,
mounting read-only
He said it wasn't like that yesterday. The likelihood of a finger check
is very minimal since the way we have these guest machines start up,
which is directly IPL it's OS disk (addr 200). My zLinux Admin tells me
that it was fine Monday before the D/R test started this morning. He
himself I guess could have finger checked, but he knows very little
about how VM works let alone issue the command to link the OS disk
device R/O.
Thank you for the suggestion on IPLing the guest into CMS first. I will
look into it again at some point when more time allows. But in the
meantime, this bizarre occurrence has puzzled us. I have since set the
console to start at IPL/startup of the guest machine to get some console
activity log to see what he's doing at startup.
Thanks for you assistance.
Kind Regards,
Steve.
From: The IBM z/VM Operating System [mailto:IBMVM@LISTSERV.UARK.EDU] On
Behalf Of RPN01
Sent: Tuesday, March 01, 2011 4:29 PM
To: IBMVM@LISTSERV.UARK.EDU
Subject: Re: zLinux OS disk read-only
You said you ended up with the disk in read-only mode, but M would imply
that if you couldn't get it in read-write mode, you wouldn't get it at
all. This would lead me to believe that there might have been fingers at
work on the console after the log-in and before the boot that might have
subsequently linked the disk, possibly with a LINK * 200 200 MR,
maybe? Again, the console log would lead to the footprint of the perp
that would tell all.
Another fine way to handle the situation and allow some control would be
to IPL the guest into CMS before starting the Linux guest. Set up the
machine using the CMS profile and do your sanity checks there, then IPL
the Linux boot disk when you know things will go well. Given our two CEC
environment, and our history before going into CSE, we use this method
to check that the image was last run on the current LPAR before IPLing
the Linux image, to be sure that it can't be running in the other CEC.
We had the same image booted on both systems at the same time once too
often, destroying the image (i.e... Once) We use a read-only CMS 191
with a profile to perform this vital sanity check (for us) before
allowing the Linux image to start. (In fact, all our linux images share
the same 191 minidisk.) Checking the Linux disks to be sure they are RW
certainly wouldn't hurt as well. It would be a simple task, especially
if you stuck to a standard addressing scheme for all your images.
Just an idea to think about.
--
Robert P. Nix Mayo Foundation.~.
RO-OC-1-18 200 First Street SW/V\
507-284-0844 Rochester, MN 55905 /( )\
-^^-^^
In theory, theory and practice are the same, but
in practice, theory and practice are different.
On 3/1/11 3:40 PM, Perez, Steve S sspe...@corelogic.com wrote:
I issued a LINK RR against it and did a Q LINKS and it shows no
other link access to that disk. Would it be possible that when we
paused PPRC and suspended Global Mirror on the z/OS LPAR (shared volumes
between all LPARS) that it may have accessed the dasd the minidisk is on
in write mode and caused the access mode on the z/VM LPAR to go into a
READ-MODE? Is that probable?
Steve.
From: The IBM z/VM Operating System
[mailto:IBMVM@LISTSERV.UARK.EDU] On Behalf Of Mark Pace
Sent: Tuesday, March 01, 2011 2:57 PM
To: IBMVM@LISTSERV.UARK.EDU
Subject: Re: zLinux OS disk read-only
M Multiple-write access. Write access is established unless
another user holds
a write, a stable (SR, SW, SM) or an exclusive (ER, EW) mode
access to
the disk.
Looks like some other VM has that disk linked in write mode.
On Tue, Mar 1, 2011 at 3:53 PM, Perez, Steve S
sspe...@corelogic.com wrote:
The disk is defined as follows. This is an excerpt
