Recover VGDA rootvg

Michael Pape

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Mar 23, 2005, 10:47:03 AM3/23/05

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Hello,
I've got a problem with a failed hdisk0 in a mirrored
rootvg. Actually I want to unmirror the rootvg to replace hdisk0
but no lvm-command is possible, resulting into the message

0516-040 : Unable to read the specified physical volume
descriptor area.

I searched WEB and news for information about recovering
from this error, but found nothing apropriate.

How can I recover a correct VGDA for the rootvg?

The System is a B50/AIX 4.3.3 ML11.

thanx for any help.
greetings,

rs6000er

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Mar 23, 2005, 12:01:59 PM3/23/05

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what is the current AIX version on your box?
and what command you are using to unmirrored the rootvg?

command lqueryvg -Atp hdiskX will show the content of vgda.
but i do not think it is really helpful.
if you want to find more lvm commands, i think IBM redbook - AIX
Logical Volume Manager from A to Z Introduction and Concepts can give
you more.

Michael Pape

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Mar 24, 2005, 4:29:10 AM3/24/05

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Hello,

I'm using AIX Version 4.3.3 ML 11
The box is a B50

So it should be possible to unmirror the rootvg with
command "unmirrorvg rootvg hdisk0"
(hdisk0 is bad)
But the actual state is, that the lqueryvg-command runs into
the following:

root@excalibur:/root> lqueryvg -Atp hdisk0
0516-040 lqueryvg: Unable to read the specified physical volume
descriptor area.
root@excalibur:/root> lqueryvg -Atp hdisk1
0516-062 lqueryvg: Unable to read or write logical volume manager
record. PV may be permanently corrupted. Run diagnostics

So I think, I have machine with to defective hdisks, and
it's running fine (but how long?).

Does anybody know a way to recover one disk online/offline
or is a reinstall the only way?

Thanx,
Michael

Laurenz Albe

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Mar 24, 2005, 5:58:32 AM3/24/05

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Michael Pape <dru...@gmx.de> wrote:
> So I think, I have machine with to defective hdisks, and
> it's running fine (but how long?).
>
> Does anybody know a way to recover one disk online/offline
> or is a reinstall the only way?

I don't know, but the first thing I would do is backup all logical volumes
on this disk. And I would not reboot.

Yours,
Laurenz Albe

Jason Liang

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Mar 25, 2005, 12:59:28 AM3/25/05

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I am afraid that you might have to recover the system from mksysb
backup.

Dohhhh

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Apr 2, 2005, 10:13:41 AM4/2/05

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Ummmm...it's been a while since I've used 4.3 but I THINK (at least at
ML11) the following should work (and your mileage may vary<G>):

smit vg
-> unmirror a volume group
-> rootvg
-> select the disk that is to be removed (I believe)
ensure the "copies" field is at 1 (if you only have 1 LV
mirror copy, which it sounds like you do)...press enter

Once done, rmdev -dl hdisk0, replace the drive (hopefully you're using
hot swappable drives - otherwise a shutdown will be required), run
cfgmgr (-v flag if you want to watch config manager do it's thing), then
reverse the above (smit vg....mirror...)

BTW, the smit menus mentioned above essentially run the following basic
commands from a prompted environment <G>

LVM:
-> unmirrorvg (or rmlvcopy for EACH LV on hdisk0)
-> reducevg (removes the drive from the VG)

KEY to helping to understand things in AIX in these cases - ESPECIALLY
the things dealing with the LVM(!!): you're working MOSTLY with the ODM
(an "object database manager" where just about everything in the system
is defined and held until told otherwise by the appropriate
command(s)...such as above.

PMS
===

byro...@neweb.com.tw

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Apr 27, 2005, 9:41:47 PM4/27/05

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before you do something please chech dump devices has to remove form
bad disk to orther devices
than:
you can run "rmlvcopy 1 LV-name hdiskx"
for each logical volume in rootvg
after you run rmlvcopy
you can run syncvg -v rootvg
than rootvg the lv/state will be synced