Generating a new UUID for XFS/EXT2/3/4 filesystems

Although very rare there will be circumstances were you encounter duplicate filesystem UUIDs.

Upon mounting one e.g.:

mount -t auto /dev/sdb1

mount: wrong fs type, bad option, bad superblock on /dev/sdb1

Tailing dmesg provides the clue as to what has gone wrong:

[ 1103.580854] XFS (xvdp1): Filesystem has duplicate UUID xxxxxx-yyyyyy-zzzzz-aaaa-bbbbbbbbbbb - can't mount

So we'll need to change the UUID of one of disks - to do this with an XFS filesystem we can use:

xfs_admin -U generate /dev/sdb1

and with the EXT family we can use:

uuidgen

<generated UUID>

tune2fs /dev/xvdp1 -U <generated UUID>

Finally attempt to remount:

mount -t auto /dev/sdb1