In this short tutorial, you are going to learn how to change the UUID of a Linux partition. This can help you in a less likely to happen scenario when the UUID of two partitions are the same.
In reality, this is really hard to happen, but it is still possible, if for example you copy a partition using dd command.
What is UUID?
UUID stands for Universally Unique IDentifier of a partition. This ID is used in 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 -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.
Conclusion
This was a short tutorial how to change a Linux partition UUID. The scenarios to use this are very rare and chances are that you will most probably use this on a local machine.
