Comment 3 for bug 1567036

From what I understand after going through online documentation, if user_friendly_names is set to yes,instead of the wwid, multipath uses names like mpatha, mpathb, etc. Otherwise it would use the wwid, like /dev/mapper/3600508b250136ef71100f002100a0000

These device names would be consistent after reboot, so if we detect a multipath setup, the charm can definitely use the /dev/mapper/XXX names and they would be consistent across reboots, even though the underlying dm-X and sdX devices may not be named the same after the reboot. What storage is referred to by mpath1, for eg, would still be referred to by that device named mpath1 after reboots. This is because multipath uses the wwids and bindings files for this purpose to provide persistent naming.