UUID stands for Universally Unique IDentifier of a partition. This ID is used in a few different places to identify the partition. Most commonly this would be /etc/fstab.
How to Find UUID of Your Filesystems
To find the UUID of your partitions, you can use blkid command as shown.
# blkid|grep UUID
How to Change UUID of Your Filesystems
Changing UUID of a filesystem is fairly easy. To do this, we are going to use tune2fs. For the purpose of this tutorial, I will change the UUID on my second partition /dev/sdb1, yours may vary, thus make sure you are changing the UUID of the desired filesystem.
The partition has to be unmounted prior apply the new UUID:
# umount /dev/sdb1 # tune2fs /dev/sdb1 -U random /dev/sdb1 # blkid | grep sdb1
The UUID has been successfully changed. Now you can mount the filesystem back again.
# mount /dev/sdb1
You can also update your /etc/fstab if needed, with the new UUID.
