Chapter 18. Persistently mounting file systems

As a system administrator, you can persistently mount file systems to configure non-removable storage.

18.1. The /etc/fstab file

Use the /etc/fstab configuration file to control persistent mount points of file systems. Each line in the /etc/fstab file defines a mount point of a file system.

It includes six fields separated by white space:

  1. The block device identified by a persistent attribute or a path in the /dev directory.
  2. The directory where the device will be mounted.
  3. The file system on the device.
  4. Mount options for the file system, which includes the defaults option to mount the partition at boot time with default options. The mount option field also recognizes the systemd mount unit options in the x-systemd.option format.
  5. Backup option for the dump utility.
  6. Check order for the fsck utility.
Note

The systemd-fstab-generator dynamically converts the entries from the /etc/fstab file to the systemd-mount units. The systemd auto mounts LVM volumes from /etc/fstab during manual activation unless the systemd-mount unit is masked.

Note

The dump utility used for backup of file systems has been removed in RHEL 9, and is available in the EPEL 9 repository.

Example 18.1. The /boot file system in /etc/fstab

Block deviceMount pointFile systemOptionsBackupCheck

UUID=ea74bbec-536d-490c-b8d9-5b40bbd7545b

/boot

xfs

defaults

0

0

The systemd service automatically generates mount units from entries in /etc/fstab.

Additional resources

  • fstab(5) and systemd.mount(5) man pages

18.2. Adding a file system to /etc/fstab

This procedure describes how to configure persistent mount point for a file system in the /etc/fstab configuration file.

Procedure

  1. Find out the UUID attribute of the file system: 

    $ lsblk --fs storage-device

    For example:

    Example 18.2. Viewing the UUID of a partition

    $ lsblk --fs /dev/sda1

NAME FSTYPE LABEL UUID                                 MOUNTPOINT
sda1 xfs    Boot  ea74bbec-536d-490c-b8d9-5b40bbd7545b /boot

  2. If the mount point directory does not exist, create it: 

    # mkdir --parents mount-point

  3. As root, edit the /etc/fstab file and add a line for the file system, identified by the UUID.

    For example:

    Example 18.3. The /boot mount point in /etc/fstab

    UUID=ea74bbec-536d-490c-b8d9-5b40bbd7545b /boot xfs defaults 0 0

  4. Regenerate mount units so that your system registers the new configuration: 

    # systemctl daemon-reload

  5. Try mounting the file system to verify that the configuration works: 

    # mount mount-point

Additional resources