Mounting typically involves the attaching of an additional filesystem to the currently accessible filesystem of a computer.
The mount command is part of the util-linux package. In Gentoo Linux, sys-apps/util-linux is part of the system set and is installed on all Gentoo systems by default.
If for some strange and unordinary reason it is missing it can be re-installed by running a simple emerge command (always use the
--oneshot option). This can also be used after changing USE flags:
emerge --ask --oneshot sys-apps/util-linux
Usage: mount [-lhV] mount -a [options] mount [options] [--source] <source> | [--target] <directory> mount [options] <source> <directory> mount <operation> <mountpoint> [<target>] Mount a filesystem. Options: -a, --all mount all filesystems mentioned in fstab -c, --no-canonicalize don't canonicalize paths -f, --fake dry run; skip the mount(2) syscall -F, --fork fork off for each device (use with -a) -T, --fstab <path> alternative file to /etc/fstab -i, --internal-only don't call the mount.<type> helpers -l, --show-labels show also filesystem labels -m, --mkdir[=<mode>] alias to '-o X-mount.mkdir[=<mode>]' -n, --no-mtab don't write to /etc/mtab --options-mode <mode> what to do with options loaded from fstab --options-source <source> mount options source --options-source-force force use of options from fstab/mtab -o, --options <list> comma-separated list of mount options -O, --test-opts <list> limit the set of filesystems (use with -a) -r, --read-only mount the filesystem read-only (same as -o ro) -t, --types <list> limit the set of filesystem types --source <src> explicitly specifies source (path, label, uuid) --target <target> explicitly specifies mountpoint --target-prefix <path> specifies path used for all mountpoints -v, --verbose say what is being done -w, --rw, --read-write mount the filesystem read-write (default) -N, --namespace <ns> perform mount in another namespace -h, --help display this help -V, --version display version Source: -L, --label <label> synonym for LABEL=<label> -U, --uuid <uuid> synonym for UUID=<uuid> LABEL=<label> specifies device by filesystem label UUID=<uuid> specifies device by filesystem UUID PARTLABEL=<label> specifies device by partition label PARTUUID=<uuid> specifies device by partition UUID ID=<id> specifies device by udev hardware ID <device> specifies device by path <directory> mountpoint for bind mounts (see --bind/rbind) <file> regular file for loopdev setup Operations: -B, --bind mount a subtree somewhere else (same as -o bind) -M, --move move a subtree to some other place -R, --rbind mount a subtree and all submounts somewhere else --make-shared mark a subtree as shared --make-slave mark a subtree as slave --make-private mark a subtree as private --make-unbindable mark a subtree as unbindable --make-rshared recursively mark a whole subtree as shared --make-rslave recursively mark a whole subtree as slave --make-rprivate recursively mark a whole subtree as private --make-runbindable recursively mark a whole subtree as unbindable For more details see mount(8).
Show mounted filesystems by running the mount command with no arguments or options:
There is also a more visual way of showing mounted filesystems using the findmnt tool also provided by sys-apps/util-linux. For more details see man 8 findmnt.
To mount a filesystem, a device file, UUID or label or other means of locating the partition or data source and a mount point are required. Non-system relevant filesystems are normally mounted in the /mnt directory. The proper syntax for mounting a file system is as follows:
mount <DEVICE> <DIRECTORY>
For further details, see man 8 mount.
The /media directory is generally used to mount removable devices such as USB drives or SD cards. After determining which device the USB drive shows up as, a command like the following could be used to mount its contents to a newly created usb folder in /media:
mount /dev/sdb1 /media/usb
A mount from fstab may by mounted by providing just the mountpoint, or device name, for example:
Unmount a filesystem
To unmount a filesystem, the device file or the mount point can be specified:
Usage: umount [-hV] umount -a [options] umount [options] <source> | <directory> Unmount filesystems. Options: -a, --all unmount all filesystems -A, --all-targets unmount all mountpoints for the given device in the current namespace -c, --no-canonicalize don't canonicalize paths -d, --detach-loop if mounted loop device, also free this loop device --fake dry run; skip the umount(2) syscall -f, --force force unmount (in case of an unreachable NFS system) -i, --internal-only don't call the umount.<type> helpers -n, --no-mtab don't write to /etc/mtab -l, --lazy detach the filesystem now, clean up things later -O, --test-opts <list> limit the set of filesystems (use with -a) -R, --recursive recursively unmount a target with all its children -r, --read-only in case unmounting fails, try to remount read-only -t, --types <list> limit the set of filesystem types -v, --verbose say what is being done -q, --quiet suppress 'not mounted' error messages -N, --namespace <ns> perform umount in another namespace -h, --help display this help -V, --version display version For more details see umount(8).
Sometimes, mounting a filesystem requires special options:
mount [OPTIONS] <DEVICE> <DIRECTORY>
||Simulate the mount|
||Specify the filesystem, e.g ext4|
||Specify the mount options (see below)|
||Mount all filesystems in /etc/fstab|
The filesystem being used must support the mount option being passed. Many options are common, but some are filesystem specific.
It is advised to always consult man pages of both mount and the particular filesystem (for example ext4 or xfs).
||Use the default mount options: |
||Mount the filesystem automatically on boot.|
||Do not mount the filesystem automatically on boot.|
||Mount the filesystem read-only.|
||Mount the filesystem read-write.|
||Mount a swap partition.|
||Update inode access times on every read.|
||Update inode access times only on writes to improve I/O performance.|
||Never update inode access times for best I/O performance.|
||Sync drive after each write. Can shorten lifespan for e.g. some flash drives.|
||Sync drive asynchronously.|
||The equivalent of trim support on Linux.|
||Allow execution of binaries.|
||Do not allow execution of binaries.|
||Follow SUID and SGID bits.|
||Do not follow SUID and SGID bits.|
||Allow a user to mount the filesystem. Implies |
||Allow every user to mount the filesystem.|
||Allow only "root" to mount the filesystem.|
Mount options of already-mounted filesystems can be changed using
remount option. For example, setting a filesystem on /dev/foo to be mounted as read-write can be achieved using:
mount -o remount,rw /dev/foo /dir
Mounting as non-superuser
According to man mount, only the superuser can mount filesystems. However, when /etc/fstab contains the
user option on a line, any user will be capable of mounting the corresponding partition, device, drive, etc.
Mounting removable media
See the relevant section in the Removable media article.
Despite /etc/fstab entries, non-superuser mounts of Windows shares will fail (for security reasons). In the following example is found a fstab entry for Windows share; pay close attention to the
[...] //server/folder /home/larry/winmount cifs noauto,user 0 0 [...]
This program is not installed setuid root - "user" CIFS mounts not supported.
The solution is to use sudo mount /home/larry/winmount in combination with a corresponding entry in /etc/sudoers to allow passwordless mounting.
Be sure to understand the sudo configuration before editing the /etc/sudoers file!
[...] larry ALL = NOPASSWD: /bin/mount /home/larry/winmount/, /bin/mount /home/larry/winmount larry ALL = NOPASSWD: /bin/umount /home/larry/winmount/, /bin/umount /home/larry/winmount [...]
- Mounting partitions in the Security Handbook
- /etc/fstab — a configuration file that defines how and where the main filesystems are to be mounted, especially at boot time.
- Removable media — any media that is easily removed from a system.
- AutoFS — a program that uses the Linux kernel automounter to automatically mount filesystems on demand.
- Udevil — a small auto-mount utility created to be a "a hassle-free replacement for udisks."
- CurlFtpFS — allows for mounting an FTP folder as a regular directory to the local directory tree.
- USB/Guide - Mounting a USB Mass Storage device
- UUIDs and labels