FSTAB(5) File Formats FSTAB(5)
fstab - static information about the filesystems
The file fstab contains descriptive information about the filesystems the system can
mount. fstab is only read by programs, and not written; it is the duty of the system
administrator to properly create and maintain this file. The order of records in fstab is
important because fsck(8), mount(8), and umount(8) sequentially iterate through fstab
doing their thing.
Each filesystem is described on a separate line. Fields on each line are separated by
tabs or spaces. Lines starting with '#' are comments. Blank lines are ignored.
The following is a typical example of an fstab entry:
LABEL=t-home2 /home ext4 defaults,auto_da_alloc 0 2
The first field (fs_spec).
This field describes the block special device or remote filesystem to be mounted.
For ordinary mounts, it will hold (a link to) a block special device node (as cre‐
ated by mknod(8)) for the device to be mounted, like `/dev/cdrom' or `/dev/sdb7'.
For NFS mounts, this field is :, e.g., `knuth.aeb.nl:/'. For filesys‐
tems with no storage, any string can be used, and will show up in df(1) output, for
example. Typical usage is `proc' for procfs; `mem', `none', or `tmpfs' for tmpfs.
Other special filesystems, like udev and sysfs, are typically not listed in fstab.