Recovering Physical Volume Metadata - Red Hat ENTERPRISE LINUX 5 - LOGICAL VOLUME MANAGER ADMINISTRATION Manual

Chapter 6. LVM Troubleshooting
[groupfs_mimage_1] vg
/dev/sda1(0)
[groupfs_mlog]
/dev/sdc1(0)

6.4. Recovering Physical Volume Metadata

If the volume group metadata area of a physical volume is accidentally overwritten or otherwise
destroyed, you will get an error message indicating that the metadata area is incorrect, or that the
system was unable to find a physical volume with a particular UUID. You may be able to recover the
data the physical volume by writing a new metadata area on the physical volume specifying the same
UUID as the lost metadata.
Warning
You should not attempt this procedure with a working LVM logical volume. You will lose
your data if you specify the incorrect UUID.
The following example shows the sort of output you may see if the metadata area is missing or
corrupted.
[root@link-07 backup]# lvs -a -o +devices
Couldn't find device with uuid 'FmGRh3-zhok-iVI8-7qTD-S5BI-MAEN-NYM5Sk'.
Couldn't find all physical volumes for volume group VG.
Couldn't find device with uuid 'FmGRh3-zhok-iVI8-7qTD-S5BI-MAEN-NYM5Sk'.
Couldn't find all physical volumes for volume group VG.
...
You may be able to find the UUID for the physical volume that was overwritten by looking in the /
etc/lvm/archive directory. Look in the file VolumeGroupName_xxxx.vg for the last known valid
archived LVM metadata for that volume group.
Alternately, you may find that deactivating the volume and setting the partial (-P) argument will
enable you to find the UUID of the missing corrupted physical volume.
[root@link-07 backup]# vgchange -an --partial
Partial mode. Incomplete volume groups will be activated read-only.
Couldn't find device with uuid 'FmGRh3-zhok-iVI8-7qTD-S5BI-MAEN-NYM5Sk'.
Couldn't find device with uuid 'FmGRh3-zhok-iVI8-7qTD-S5BI-MAEN-NYM5Sk'.
...
Use the --uuid and --restorefile arguments of the pvcreate command to restore the physical
volume. The following example labels the /dev/sdh1 device as a physical volume with the UUID
indicated above, FmGRh3-zhok-iVI8-7qTD-S5BI-MAEN-NYM5Sk. This command restores the
physical volume label with the metadata information contained in VG_00050.vg, the most recent
good archived metatdata for volume group . The restorefile argument instructs the pvcreate
command to make the new physical volume compatible with the old one on the volume group,
ensuring that the the new metadata will not be placed where the old physical volume contained data
72
iwi-ao 752.00M
vg lwi-ao 4.00M