How to change disk partition UUID in Linux

Most major Linux distributions create and assign UUID on disk partitions during system installation, which is then used as an identifier to mount the partition in /etc/fstab. Once set, UUID is static, and it addresses the issue with partition's device name that could change, which causes the fstab to no longer be valid and the filesystem not mounted.

You can create and assign UUID on newly created partitions or change UUID on existing partitions in Linux from the terminal.

1. Launch the terminal application.
2. Generate UUID using uuidgen.

   $ uuidgen
   39ea80c4-e748-47eb-835c-64025de53e26

   uuidgen is normally installed by default in most Linux systems.

   You can also get UUID from /proc/sys/kernel/random/uuid.

   $ cat /proc/sys/kernel/random/uuid
   5c27b2b3-58f4-4469-a717-45865f517400

3. Make sure the partition that you want to assign the UUID is not mounted.

   $ sudo umount /dev/sdb1

4. Run filesystem check on the partition.

   $ sudo e2fsck -f /dev/sdb1
   e2fsck 1.44.6 (5-Mar-2019)
   Pass 1: Checking inodes, blocks, and sizes
   Pass 2: Checking directory structure
   Pass 3: Checking directory connectivity
   Pass 4: Checking reference counts
   Pass 5: Checking group summary information
   /dev/sdb1: 11/1310720 files (0.0% non-contiguous), 126322/5242624 blocks

5. Assign UUID to partition using tune2fs.

   $ sudo tune2fs /dev/sdb1 -U 39ea80c4-e748-47eb-835c-64025de53e26
   tune2fs 1.44.6 (5-Mar-2019)
   Setting the UUID on this filesystem could take some time.
   Proceed anyway (or wait 5 seconds to proceed) ? (y,N) y

6. Check if UUID is properly assigned to the partition.

   $ sudo blkid /dev/sdb1
   /dev/sdb1: UUID="39ea80c4-e748-47eb-835c-64025de53e26" TYPE="ext4" PARTUUID="2c6a7a3a-01"