Symptom

If Full System Backup is enabled on Linux, the following warning is shown on backup if any mounts with names starting with /dev/sd* or /dev/disk/by-path/* are present in /etc/fstab:

Non persistent path '/dev/sdc1' in '/etc/fstab' could cause issues with Linux Full System Recovery (see FAQ https://bit.ly/3edHkaD)

 

Cause

Various factors may affect the order in which connected devices are discovered and numbered by the Linux kernel at boot time. The process of restoring to Azure often results in storage device names that differ from those on the source machine. As a result, a machine using non-persistent device names in /etc/fstab may not boot successfully after Full System Recovery.

 

Solution

To avoid FSR problems resulting from the presence of non-persistent paths in /etc/fstab, we highly recommend that you convert your mounts to use UUIDs. For example:

If /etc/fstab contains the following mount:

/dev/sdc1 /data ext4 defaults 0 2

use the blkid command to find the corresponding filesystem UUID:

$ sudo blkid | grep /dev/sdc1
/dev/sdc1: UUID="9a29b66b-a2a2-4df7-927b-546f73e52953" TYPE="ext4" PARTUUID="d381e10e-01"

and replace the device /dev/sdc1 in /etc/fstab with the filesystem UUID:

UUID=9a29b66b-a2a2-4df7-927b-546f73e52953 /data ext4 defaults 0 2

 

See also: