Mirrored root disk

[Karthik S S]

Hi,

As a part of Service guard testing I removed the internal HDD of rp8400 which has an OS mirror while working. The removal though not recommended, worked fine but when it was plugged in online, the LVM did not recognize the HDD. It was claimed in ioscan but the vgsync reported disk missing. Any solutions ?

Thanks,
Karthik S S

[James Murtagh · Accepted solution]

Hi Karthik,

You'll need to bring it back under LVM control by running :

# vgchange -a y vg00

This will sync it automatically, use the -s option too if you don't want this to happen.

cheers,

James.

[Sridhar Bhaskarla]

Hi Karthik,

You will need to do 'vgchange -a y vg00' following 'vgsync' as mentioned by James.

-Sri

[G. Vrijhoeven]

Hi K.

Just to be sure but is your root disk part of the cluster (cluster awaire)? If so use the option James gave. If not i am afraid the you just can go for the removal of the lvmtab and a vgscan to recreate it.

Gideon

[Chung, jin-won]

Hi Karthik.
You missed one process after re-plugging hdd. HDD of rp8400 is not hot swappable, it's just hot pluggable.
you can plug it in online.
You have to execute following command after plugging
vgcfgrestore -n vg00 /dev/dsk/cXtXdX

have a good day

[Sridhar Bhaskarla]

No need of vgcfgrestore. It is required only if the disk doesn't have the VGRA. This would be due to either corruption or if you replaced a bad disk with a new disk.

vgchange -a y vg00 should settle down the things as the disk has already got the information. vgsync will be automatically kicked as the extents would become stale.

-Sri

[Trond Haugen]

Just to add to Sridhars answer;
vgcfgrestore would write the backup of the LVM disk header back to the disk. That would only have been usefull had you put in a brand new disk. You would then also have had to put in the LIF in order to be able to boot. (pvcreate -B ....

vgchange -a y and posibly a vgsync should only sync the few stale extents.

Regards,
Trond