fstab
filesystem mount configuration file
TLDR
View fstab
$ cat /etc/fstab
Check fstab syntax$ sudo mount -a
Show mounted filesystems$ findmnt
DESCRIPTION
/etc/fstab is a configuration file that defines how filesystems are mounted at boot time. Each line describes a filesystem, mount point, type, options, and backup/check settings.The file is read by mount and systemd to automatically mount filesystems during system startup.
FILE FORMAT
$ <device> <mountpoint> <type> <options> <dump> <pass>
/dev/sda1 /boot ext4 defaults 0 2
UUID=abc123 /home ext4 defaults,noatime 0 2
/dev/sda3 none swap sw 0 0
//server/share /mnt/share cifs credentials=/etc/creds 0 0
/dev/sda1 /boot ext4 defaults 0 2
UUID=abc123 /home ext4 defaults,noatime 0 2
/dev/sda3 none swap sw 0 0
//server/share /mnt/share cifs credentials=/etc/creds 0 0
FIELDS
device
Device, UUID, LABEL, or network path.mountpoint
Where to mount (directory or "none" for swap).type
Filesystem type (ext4, xfs, btrfs, nfs, cifs, swap).options
Mount options, comma-separated.dump
Backup flag (usually 0).pass
fsck order (0=skip, 1=root, 2=other).
COMMON OPTIONS
$ defaults - rw,suid,dev,exec,auto,nouser,async
noauto - Don't mount at boot
nofail - Don't fail boot if device missing
ro - Read-only
noexec - Don't allow execution
nosuid - Ignore setuid bits
noatime - Don't update access times
user - Allow non-root users to mount
noauto - Don't mount at boot
nofail - Don't fail boot if device missing
ro - Read-only
noexec - Don't allow execution
nosuid - Ignore setuid bits
noatime - Don't update access times
user - Allow non-root users to mount
CAVEATS
Errors can prevent boot. Always test with `mount -a` before reboot. Use UUID or LABEL for reliable device identification. Network mounts need special handling.