How to mount a disk partition by UUID in Linux

Kernel device names can change when disks are added, controllers are reordered, or a virtual machine boots with different storage timing. Mounting by filesystem UUID keeps a data volume tied to the intended directory even when the kernel assigns a different device name.

Each filesystem stores its own UUID in metadata on the device. blkid reads that identifier and the filesystem type, mount can resolve a UUID=… source, and the system mount table can save the same stable reference for future mounts.

The examples below use an ext4 filesystem and a persistent local data mount. Replace the device path, UUID, filesystem type, mount point, mount options, and final check field for the target filesystem, because a malformed persistent mount entry can leave the volume unavailable during boot.

1. List the target block device before changing any mount configuration.

   $ lsblk -o NAME,SIZE,TYPE,MOUNTPOINTS /dev/vdb1
   NAME  SIZE TYPE MOUNTPOINTS
   vdb1   64G part

   Use the filesystem device, usually a partition such as /dev/vdb1, /dev/sdb1, /dev/nvme1n1p1, or a logical volume under /dev/mapper. If MOUNTPOINTS already shows a path, the filesystem is already mounted.

2. Read the filesystem UUID and type from the target device.

   $ sudo blkid /dev/vdb1
   /dev/vdb1: LABEL="data" UUID="fcc7979c-742b-43aa-9fe5-6a014e23496f" BLOCK_SIZE="4096" TYPE="ext4"

3. Create the mount point directory.

   $ sudo mkdir -p /mnt/data

   Files already present in the mount point directory stay hidden while another filesystem is mounted there.

4. Test a direct mount by UUID before saving persistent configuration.

   $ sudo mount UUID=fcc7979c-742b-43aa-9fe5-6a014e23496f /mnt/data

5. Confirm that the UUID resolved to the intended device and mount point.

   $ findmnt -M /mnt/data -o TARGET,SOURCE,FSTYPE,OPTIONS
   TARGET    SOURCE    FSTYPE OPTIONS
   /mnt/data /dev/vdb1 ext4   rw,relatime

   The -M option checks the exact mount point instead of walking up parent directories.

6. Unmount the test mount before editing /etc/fstab.

   $ sudo umount /mnt/data

7. Back up the current /etc/fstab file.

   $ sudo cp --archive /etc/fstab /etc/fstab.bak

   A malformed /etc/fstab entry can delay boot or leave the filesystem unavailable until the file is corrected.

8. Open /etc/fstab in an editor with root privileges.

   $ sudoedit /etc/fstab

9. Add a persistent mount line that uses the UUID instead of the raw device path.

   UUID=fcc7979c-742b-43aa-9fe5-6a014e23496f /mnt/data ext4 defaults 0 2

   The fields are source, mount point, filesystem type, mount options, dump flag, and filesystem check order. Use 0 0 for filesystems that should not be checked by fsck at boot, and consider defaults,nofail for storage that may be absent during boot.

10. Verify the saved /etc/fstab entry before mounting from it.

    $ sudo findmnt --verify --verbose /mnt/data
    /mnt/data
       [ ] target exists
       [ ] UUID=fcc7979c-742b-43aa-9fe5-6a014e23496f translated to /dev/vdb1
       [ ] source /dev/vdb1 exists
       [ ] FS type is ext4
    Success, no errors or warnings detected

    Correct the /etc/fstab line before continuing if findmnt reports an error or warning.

11. Mount the saved entry by its mount point.

    $ sudo mount /mnt/data

12. Confirm that the persistent entry mounted the expected filesystem.

    $ findmnt -M /mnt/data -o TARGET,SOURCE,FSTYPE,OPTIONS
    TARGET    SOURCE    FSTYPE OPTIONS
    /mnt/data /dev/vdb1 ext4   rw,relatime