7. /etc/fstab

When we want to automatically mount filesystems at startup we can add them to a file called /etc/fstab (pronounced "eff es tab" not "eff stab") short for filesystem table. This file contains a permanent list of filesystems that are mounted.


pete@icebox:~$ cat /etc/fstab
UUID=130b882f-7d79-436d-a096-1e594c92bb76 / ext4 relatime,errors=remount-ro 0 1
UUID=78d203a0-7c18-49bd-9e07-54f44cdb5726 /home xfs relatime 0 2
UUID=22c3d34b-467e-467c-b44d-f03803c2c526 none swap sw 0 0

Each line represents one filesystem, the fields are:


  • UUID - Device identifier

  • Mount point - Directory the filesystem is mounted to

  • Filesystem type

  • Options - other mount options, see manpage for more details

  • Dump - used by the dump utility to decide when to make a backup, you should just default to 0

  • Pass - Used by fsck to decide what order filesystems should be checked, if the value is 0, it will not be checked

To add an entry, just directly modify the /etc/fstab file using the entry syntax above. Be careful when modifying this file, you could potentially make your life a little harder if you mess up.

Exercises

Add the USB drive we've been working on as a entry in /etc/fstab, when you reboot you should still see it mounted.

Quiz

What file is used to define how filesystems should be mounted?