topic Re: mirror disk replacement - gone horribly wrong in Operating System - HP-UX

mirror disk replacement - gone horribly wrong

Adam Noble — Tue, 23 Jan 2007 04:53:47 GMT

Hi all,

Last night we had our mirrored root disk replaced by an engineer. The process he followed was clearly wrong which involved initially replacing the disk online and then re-booting. There needed to be a step in the middle where the server was brought into single user or maintenance mode and the vgcfgrestore command ran. Ok the server did re-boot however its not in a great state now. The filesystems are mounted and application running however vgdisplay claims the replacement disk which is showing as claimed cannot be queried. I guess this is because it has no header info. Ideally it would be great if we could just get this disk out of the vg00 config but that is not possible. I am also very concerned by the vgscan -p (preview) output which claims it cannot re-create the lvmtab file so I can't re-create. It says:-

]vgscan -p
vgscan: Warning: couldn't query physical volume "/dev/dsk/c7t6d0":
The specified path does not correspond to physical volume attached to
this volume group
vgscan: Warning: couldn't query all of the physical volumes.
vgscan: The physical volume "/dev/dsk/c4t6d0" is already recorded in the "/etc/lvmtab" file.
vgscan: The physical volume "/dev/dsk/c7t6d0" is already recorded in the "/etc/lvmtab" file.
Physical Volume "/dev/dsk/c5t2d0" contains no LVM information
Physical Volume "/dev/dsk/c7t6d0" contains no LVM information

vgscan: has no correspoding valid raw device file under /dev/rdsk.
Verification of unique LVM disk id on each disk in the volume group

I can't pvcreate the disk or anthing as its referenced in lvmtab.....HP are investigating but I thought I'd ask the question here as usually get a good response.

Re: mirror disk replacement - gone horribly wrong

Steven E. Protter — Tue, 23 Jan 2007 05:36:52 GMT

Shalom,

Yes a mistake was clearly made.

Try this:

mv /etc/lvmtab /etc/lvmtab.save

vgscan -a

Follow any instructions after that displayed by the utility and see if you can pvcreate after clearing the problem.

SEP

Re: mirror disk replacement - gone horribly wrong

Adam Noble — Tue, 23 Jan 2007 05:40:47 GMT

The problem is as explained above its not letting me vgscan

vgscan -a -p
vgscan: The physical volume "/dev/dsk/c4t6d0" is already recorded in the "/etc/lvmtab " file.
vgscan: The physical volume "/dev/dsk/c7t6d0" is already recorded in the "/etc/lvmtab " file.
Physical Volume "/dev/dsk/c5t2d0" contains no LVM information
Physical Volume "/dev/dsk/c7t6d0" contains no LVM information

vgscan: has no correspoding valid raw device file under /dev/rdsk.
Verification of unique LVM disk id on each disk in the volume group
/dev/vg00 failed.

Re: mirror disk replacement - gone horribly wrong

Pete Randall — Tue, 23 Jan 2007 05:56:06 GMT

Exactly, you can't vgscan because the new disk has no LVM info. I believe you need to run your vgcfgrestore, then follow the normal steps for mirrored root disk replacement:

http://docs.hp.com/en/5991-1236/When_Good_Disks_Go_Bad.pdf

Pete