However, when fstab contains the user option on a line, anybody can mount the corresponding system. Normally, only the superuser can mount filesystems. When you have very large numbers of mounts things are much faster with the symlink, but some information is lost that way in particular, the " user" option fails. It is possible to replace /etc/mtab by a symbolic link to /proc/mounts. The former has somewhat more information, such as the mount options used, but is not necessarily up-to-date (compare with the -n option below). When the proc filesystem is mounted (at /proc, for instance), the files /etc/mtab and /proc/mounts have very similar contents. If there are duplicate options, the usual behavior is that the one occurring last in the command is used. If you want to override mount options from /etc/fstab, you have to use: mount device| dir -o optionsĪnd then the mount options from command line is appended to the list of options from /etc/fstab. The mount program does not read the /etc/fstab file if both device (or LABEL/ UUID) and dir are specified. If no arguments are given to mount, this list is printed. The programs mount and umount maintain a list of currently mounted filesystems in the file /etc/mtab. When mounting a filesystem mentioned in fstab or mtab, it suffices to give only the device, or only the mount point. Adding the -F option makes mount fork, so that the filesystems are mounted simultaneously. This command is often included in a boot script. The command mount -a Ĭauses all filesystems mentioned in fstab (of the proper type and/or having or not having the proper options) to be mounted as indicated, except for those whose line contains the noauto keyword. The file /etc/fstab may contain lines describing what devices are usually mounted where, using which options. The Files /etc/fstab, /etc/mtab And /proc/mounts The customary choice none is less fortunate: the error message " none busy" from umount can be confusing since something is indeed busy. The proc filesystem is not associated with a special device, and when mounting it, an arbitrary keyword such as proc can be used instead of a device specification.
The string representation of the UUID should be based on lowercase characters. The UUIDs from command line or fstab are not converted to internal binary representation. Internally, mount command uses udev symlinks, so using symlinks in /etc/fstab has no advantage over " LABEL=/UUID=". The tags are more readable, robust and portable.
] device| dir mount device| dir umount syntax umount umount -a umount " udev symlinks in the /etc/fstab file.