Home > Storage > PowerVault > Guides > Dell PowerVault ME4 Series and Linux > Mounting snapshots to recover data
Snapshots are useful to recover data that is deleted, corrupted, or changed unintentionally on the source volumes. Mount a snapshot created before the unintentional change happened on an alternate host and retrieve the data using the appropriate tools, such as cp, dd, or application-specific utilities. If data resides on multiple volumes, the corresponding snapshots of the volumes must be made available to the host.
If the snapshots are mapped to the same host as the source host, additional steps are necessary to mount the snapshots because the metadata on the snapshot volumes are exactly the same as the source volumes. This metadata such as disk label, UUID, and volume group metadata, conflicts with existing mounted volumes. It is recommended to mount snapshots on an alternate host instead. However, if the same source host must be used, use the following procedures to modify the metadata on the snapshots. The snapshot volumes need to be mapped to the host with read-write access.
# vgimportclone –-basevgname vgme-snapshot /dev/mapper/mpathz
# uuidgen
09d56888-eb9f-4a8d-9e9e-bca028edf4ef
# xfs_admin -U 09d56888-eb9f-4a8d-9e9e-bca028edf4ef /dev/mapper/mpathe
Clearing log and setting UUID
writing all SBs
new UUID = 09d56888-eb9f-4a8d-9e9e-bca028edf4ef
Use the uuidgen and tune2fs -U command to change the filesystem UUID to the new UUID.
# uuidgen
6028cf0d-9a0a-4150-99ab-3ff35c6fd550
# tune2fs /dev/mapper/mpathg -U 6028cf0d-9a0a-4150-99ab-3ff35c6fd550
tune2fs 1.42.9 (28-Dec-2013)
# blkid /dev/mapper/mpathg
/dev/mapper/mpathg: UUID="6028cf0d-9a0a-4150-99ab-3ff35c6fd550" TYPE="ext4"
Note: Without changing the UUIDs, the snapshot volume group and file system cannot be mounted on the same system.