"Unknown" Errors in pvs or vgs ​

Symptom ​

When running pvs or vgs commands, physical volumes (PVs) or volume groups (VGs) may display "unknown" status.

Possible Causes ​

This issue typically occurs due to corrupted metadata, preventing the system from reading complete information about the storage components. The affected PV or VG becomes unusable until repaired. For verification, you can examine raw disk data using the hexdump utility (see LVM Label Corruption for details).

Solution ​

Fixing Unrecognized VGs ​

pvck --repair --file /etc/lvm/backup/vg /dev/sdb

VG backup files are stored in /etc/lvm/backup.

Repairing Unrecognized PVs ​

pvcreate --uuid xxx --restorefile /etc/lvm/backup/vg /dev/sdc
vgcfgrestore --file /etc/lvm/backup/vg vg
vgchange -ay vg

The UUID can be found in the backup files located at /etc/lvm/backup. After performing these repairs, verify the fix by running pvs or vgs again. Normal output indicates successful restoration.