topic Re: Failed mirrored disk? in Operating System - HP-UX

Failed mirrored disk?

Henry Goverde — Tue, 25 Jun 2002 11:32:13 GMT

Hi,
We had 1 disk of a mirrored set fail. This disk contained a mirror of lvol7 (/usr) and lvol8 (/var). I removed the disk and replaced it with a new one, but I can't seem to get rid of the "ghost" disk from lvmtab. The system will not allow me to add the new disk without first removing the dead one.
I probably screwed up in my replacement proceedure, but is there a painless way to get rid of this disk.

Thanks in advance,
Henry

Re: Failed mirrored disk?

T G Manikandan — Tue, 25 Jun 2002 11:38:50 GMT

Document from HP

http://forums.itrc.hp.com/cm/components/FileAttachment/0,,0x18d0e7726eccd5118ff10090279cd0f9,00.htm

Also check this link for some good points from the seniors.

http://forums.itrc.hp.com/cm/QuestionAnswer/0,,0xd5cfe7726eccd5118ff10090279cd0f9,00.html

Thanks
G Manikandan

Re: Failed mirrored disk?

Carlos Fernandez Riera — Tue, 25 Jun 2002 11:39:48 GMT

You must do a vgcfgrestore and that disk, you dont need to do a vgreduce.

See http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0x976b50011d20d6118ff40090279cd0f9,00.html.

Re: Failed mirrored disk?

Henry Goverde — Tue, 25 Jun 2002 12:27:52 GMT

Thanks again for the information.

Re: Failed mirrored disk?

George Abraham_1 — Tue, 25 Jun 2002 14:29:56 GMT

hai

try this

#vgcfgrestore -n vg_name /dev/rdsk/c?t?d?
#vgsync

this should do the fixing

Re: Failed mirrored disk?

Sanjay_6 — Tue, 25 Jun 2002 14:37:39 GMT

Hi,

Instead of adding the new disk as an additional disk you should have just restored the VG info to that disk,

vgcfgrestore -n vg00 /dev/rdsk/cxtydz

And then done a vgsync.

vgsync /dev/vg00

Hope this helps.

Regds

Re: Failed mirrored disk?

Henry Goverde — Tue, 25 Jun 2002 15:09:31 GMT

I was able to get the new disk recognized and added to the vg. My only issue now is that the kernel still thinks the "dead disk" is in the system and part of vg00. It will not let me re-mirror the logical volumes.

Is there a way to get the kernel to throw out the "dead disk"?

Thanks,

Henry

Re: Failed mirrored disk?

George Abraham_1 — Tue, 25 Jun 2002 20:07:48 GMT

hai

you can try updating the lvmtab by using vgscan.. this should refresh the kernel about the dead disk

regards
george

Re: Failed mirrored disk?

Deshpande Prashant — Tue, 25 Jun 2002 20:12:55 GMT

HI
Try,
#mv /etc/lvmtab /etc/lvmtab.OLD
#vgscan -av

Thanks.
Prashant.

Re: Failed mirrored disk?

Jeff Schussele — Tue, 25 Jun 2002 20:20:21 GMT

Hi Henry,

The KEY is to rename or mv the lvmtab file *before* you vgscan. Else vgscan uses the exixting info in lvmtab to *rebuild* the new lvmtab. If you don't mv it it will remain in the lvmtab file.

Rgds,
Jeff

Re: Failed mirrored disk?

Jon Finley — Tue, 25 Jun 2002 21:56:55 GMT

Ahhh the insidious kernel has 3 disks while lvmtab has only 2.......

Two ways of approching the problem.

You can try moving lvmtab, an use vgscan to re-create lvmtab.

Or.. the REALLY ugly way..

Remove the "missing" disk by key.

I'm using vg00 and c1t0d0 as an example.

lvdisplay -v /dev/vg00/lvol1 | more

Note the column position for the disk with '???'.

lvdisplay -v -k /dev/vg00/lvol1 | more

Note the key value of the same disk this time.
(in this example I'll use '1').

then:

lvreduce -m 0 -k /dev/vg00/lvol8 1
lvreduce -m 0 -k /dev/vg00/lvol7 1
lvreduce -m 0 -k /dev/vg00/lvol6 1
lvreduce -m 0 -k /dev/vg00/lvol5 1
lvreduce -m 0 -k /dev/vg00/lvol4 1
lvreduce -m 0 -k /dev/vg00/lvol3 1
lvreduce -m 0 -k /dev/vg00/lvol2 1
lvreduce -m 0 -k /dev/vg00/lvol1 1

then:

vgreduce -f /dev/vg00

Follow the instructions given after the command completes (move lvmtab, vgscan, vgcfgbackup).

Phantom disk should now be gone.

Jon