findmnt(8) — Linux manual page

NAME | SYNOPSIS | DESCRIPTION | OPTIONS | EXIT STATUS | ENVIRONMENT | EXAMPLES | AUTHORS | SEE ALSO | REPORTING BUGS | AVAILABILITY

FINDMNT(8)                System Administration               FINDMNT(8)

NAME         top

       findmnt - find a filesystem

SYNOPSIS         top

       findmnt [options]

       findmnt [options] device|mountpoint

       findmnt [options] [--source] device [--target path|--mountpoint
       mountpoint]

DESCRIPTION         top

       findmnt will list all mounted filesystems or search for a
       filesystem. The findmnt command is able to search in /etc/fstab,
       /etc/mtab or /proc/self/mountinfo. If device or mountpoint is not
       given, all filesystems are shown.

       The device may be specified by device name, major:minor numbers,
       filesystem label or UUID, or partition label or UUID. Note that
       findmnt follows mount(8) behavior where a device name may be
       interpreted as a mountpoint (and vice versa) if the --target,
       --mountpoint or --source options are not specified.

       The command-line option --target accepts any file or directory
       and then findmnt displays the filesystem for the given path.

       The command prints all mounted filesystems in the tree-like
       format by default. The default output, is subject to change. So
       whenever possible, you should avoid using default output in your
       scripts. Always explicitly define expected columns by using
       --output columns-list in environments where a stable output is
       required.

       The relationship between block devices and filesystems is not
       always one-to-one. The filesystem may use more block devices.
       This is why findmnt provides  SOURCE and SOURCES (pl.) columns.
       The column SOURCES displays all devices where it is possible to
       find the same filesystem  UUID (or another tag specified in fstab
       when executed with --fstab and --evaluate).

OPTIONS         top

       -A, --all
           Disable all built-in filters and print all filesystems.

       -a, --ascii
           Use ascii characters for tree formatting.

       -b, --bytes
           Print the sizes in bytes rather than in a human-readable
           format.

           By default, the unit, sizes are expressed in, is byte, and
           unit prefixes are in power of 2^10 (1024). Abbreviations of
           symbols are exhibited truncated in order to reach a better
           readability, by exhibiting alone the first letter of them;
           examples: "1 KiB" and "1 MiB" are respectively exhibited as
           "1 K" and "1 M", then omitting on purpose the mention "iB",
           which is part of these abbreviations.

       -C, --nocanonicalize
           Do not canonicalize paths at all. This option affects the
           comparing of paths and the evaluation of tags (LABEL, UUID,
           etc.).

       -c, --canonicalize
           Canonicalize all printed paths.

       --deleted
           Print filesystems where target (mountpoint) is marked as
           deleted by kernel.

       -D, --df
           Imitate the output of df(1). This option is equivalent to -o
           SOURCE,FSTYPE,SIZE,USED,AVAIL,USE%,TARGET but excludes all
           pseudo filesystems. Use --all to print all filesystems.

       -d, --direction word
           The search direction, either forward or backward.

       -e, --evaluate
           Convert all tags (LABEL, UUID, PARTUUID, or PARTLABEL) to the
           corresponding device names for the SOURCE column. It’s an
           unusual situation, but the same tag may be duplicated (used
           for more devices). For this purpose, there is SOURCES (pl.)
           column. This column displays by multi-line cell all devices
           where the tag is detected by libblkid. This option makes
           sense for fstab only.

       -F, --tab-file path
           Search in an alternative file. If used with --fstab, --mtab
           or --kernel, then it overrides the default paths. If
           specified more than once, then tree-like output is disabled
           (see the --list option).

       -f, --first-only
           Print the first matching filesystem only.

       -H, --list-columns
           List the available columns, use with --json or --raw to get
           output in machine-readable format.

       -i, --invert
           Invert the sense of matching.

       -J, --json
           Use JSON output format.

       -k, --kernel
           Search in /proc/self/mountinfo. The output is in the
           tree-like format. This is the default. The output contains
           only mount options maintained by kernel (see also --mtab).

       -l, --list
           Use the list output format. This output format is
           automatically enabled if the output is restricted by the -t,
           -O, -S or -T option and the option --submounts is not used or
           if more that one source file (the option -F) is specified.

       -M, --mountpoint path
           Explicitly define the mountpoint file or directory. See also
           --target.

       -m, --mtab
           Search in /etc/mtab. The output is in the list format by
           default (see --tree). The output may include user space mount
           options.

       -N, --task tid
           Use alternative namespace /proc/<tid>/mountinfo rather than
           the default /proc/self/mountinfo. If the option is specified
           more than once, then tree-like output is disabled (see the
           --list option). See also the unshare(1) command.

       -n, --noheadings
           Do not print a header line.

       -O, --options list
           Limit the set of printed filesystems. More than one option
           may be specified in a comma-separated list. The -t and -O
           options are cumulative in effect. It is different from -t in
           that each option is matched exactly; a leading no at the
           beginning does not have global meaning. The "no" can used for
           individual items in the list. The "no" prefix interpretation
           can be disabled by "+" prefix.

       -o, --output list
           Define output columns. See the --help output to get a list of
           the currently supported columns. The TARGET column contains
           tree formatting if the --list or --raw options are not
           specified.

           The default list of columns may be extended if list is
           specified in the format +list (e.g., findmnt -o
           +PROPAGATION).

       --output-all
           Output almost all available columns. The columns that require
           --poll are not included.

       -P, --pairs
           Produce output in the form of key="value" pairs. All
           potentially unsafe value characters are hex-escaped
           (\x<code>). See also option --shell.

           Note that SOURCES column, use multi-line cells. In these
           cases, the column use an array-like formatting in the output,
           for example name=("aaa" "bbb" "ccc").

       -p, --poll[=list]
           Monitor changes in the /proc/self/mountinfo file. Supported
           actions are: mount, umount, remount and move. More than one
           action may be specified in a comma-separated list. All
           actions are monitored by default.

           The time for which --poll will block can be restricted with
           the --timeout or --first-only options.

           The standard columns always use the new version of the
           information from the mountinfo file, except the umount action
           which is based on the original information cached by findmnt.
           The poll mode allows using extra columns:

           ACTION
               mount, umount, move or remount action name; this column
               is enabled by default

           OLD-TARGET
               available for umount and move actions

           OLD-OPTIONS
               available for umount and remount actions

       --pseudo
           Print only pseudo filesystems.

       --shadow
           Print only filesystems over-mounted by another filesystem.

       -R, --submounts
           Print recursively all submounts for the selected filesystems.
           The restrictions defined by options -t, -O, -S, -T and
           --direction are not applied to submounts. All submounts are
           always printed in tree-like order. The option enables the
           tree-like output format by default. This option has no effect
           for --mtab or --fstab.

       -r, --raw
           Use raw output format. All potentially unsafe characters are
           hex-escaped (\x<code>).

           Note that column SOURCES, use multi-line cells. In these
           cases, the column may produce more strings on the same line.

       --real
           Print only real filesystems.

       -S, --source spec
           Explicitly define the mount source. Supported specifications
           are device, maj:min, LABEL=label, UUID=uuid, PARTLABEL=label
           and PARTUUID=uuid.

       -s, --fstab
           Search in /etc/fstab. The output is in the list format (see
           --list).

       -T, --target path
           Define the mount target. If path is not a mountpoint file or
           directory, then findmnt checks the path elements in reverse
           order to get the mountpoint (this feature is supported only
           when searching in kernel files and unsupported for --fstab).
           It’s recommended to use the option --mountpoint when checks
           of path elements are unwanted and path is a strictly
           specified mountpoint.

       -t, --types list
           Limit the set of printed filesystems. More than one type may
           be specified in a comma-separated list. The list of
           filesystem types can be prefixed with no to specify the
           filesystem types on which no action should be taken. For more
           details see mount(8).

       --tree
           Enable tree-like output if possible. The options is silently
           ignored for tables where is missing child-parent relation
           (e.g., fstab).

       --shadowed
           Print only filesystems over-mounted by another filesystem.

       -U, --uniq
           Ignore filesystems with duplicate mount targets, thus
           effectively skipping over-mounted mount points.

       -u, --notruncate
           Do not truncate text in columns. The default is to not
           truncate the TARGET, SOURCE, UUID, LABEL, PARTUUID, PARTLABEL
           columns. This option disables text truncation also in all
           other columns.

       -v, --nofsroot
           Do not print a [/dir] in the SOURCE column for bind mounts or
           btrfs subvolumes.

       -w, --timeout milliseconds
           Specify an upper limit on the time for which --poll will
           block, in milliseconds.

       -x, --verify
           Check mount table content. The default is to verify
           /etc/fstab parsability and usability. It’s possible to use
           this option also with --tab-file. It’s possible to specify
           source (device) or target (mountpoint) to filter mount table.
           The option --verbose forces findmnt to print more details.

       --verbose
           Force findmnt to print more information (--verify only for
           now).

       --vfs-all
           When used with VFS-OPTIONS column, print all VFS
           (fs-independent) flags. This option is designed for auditing
           purposes to list also default VFS kernel mount options which
           are normally not listed.

       -y, --shell
           The column name will be modified to contain only characters
           allowed for shell variable identifiers. This is usable, for
           example, with --pairs. Note that this feature has been
           automatically enabled for --pairs in version 2.37, but due to
           compatibility issues, now it’s necessary to request this
           behavior by --shell.

       -h, --help
           Display help text and exit.

       -V, --version
           Print version and exit.

EXIT STATUS         top

       The exit value is 0 if there is something to display, or 1 on any
       error (for example if no filesystem is found based on the user’s
       filter specification, or the device path or mountpoint does not
       exist).

ENVIRONMENT         top

       LIBMOUNT_FSTAB=<path>
           overrides the default location of the fstab file

       LIBMOUNT_MTAB=<path>
           overrides the default location of the mtab file

       LIBMOUNT_DEBUG=all
           enables libmount debug output

       LIBSMARTCOLS_DEBUG=all
           enables libsmartcols debug output

       LIBSMARTCOLS_DEBUG_PADDING=on
           use visible padding characters.

EXAMPLES         top

       findmnt --fstab -t nfs
           Prints all NFS filesystems defined in /etc/fstab.

       findmnt --fstab /mnt/foo
           Prints all /etc/fstab filesystems where the mountpoint
           directory is /mnt/foo. It also prints bind mounts where
           /mnt/foo is a source.

       findmnt --fstab --target /mnt/foo
           Prints all /etc/fstab filesystems where the mountpoint
           directory is /mnt/foo.

       findmnt --fstab --evaluate
           Prints all /etc/fstab filesystems and converts LABEL= and
           UUID= tags to the real device names.

       findmnt -n --raw --evaluate --output=target LABEL=/boot
           Prints only the mountpoint where the filesystem with label
           "/boot" is mounted.

       findmnt --poll --mountpoint /mnt/foo
           Monitors mount, unmount, remount and move on /mnt/foo.

       findmnt --poll=umount --first-only --mountpoint /mnt/foo
           Waits for /mnt/foo unmount.

       findmnt --poll=remount -t ext3 -O ro
           Monitors remounts to read-only mode on all ext3 filesystems.

AUTHORS         top

       Karel Zak <kzak@redhat.com>

SEE ALSO         top

       fstab(5), mount(8)

REPORTING BUGS         top

       For bug reports, use the issue tracker at
       https://github.com/util-linux/util-linux/issues.

AVAILABILITY         top

       The findmnt command is part of the util-linux package which can
       be downloaded from Linux Kernel Archive
       <https://www.kernel.org/pub/linux/utils/util-linux/>. This page
       is part of the util-linux (a random collection of Linux
       utilities) project. Information about the project can be found at
       ⟨https://www.kernel.org/pub/linux/utils/util-linux/⟩. If you have
       a bug report for this manual page, send it to
       util-linux@vger.kernel.org. This page was obtained from the
       project's upstream Git repository
       ⟨git://git.kernel.org/pub/scm/utils/util-linux/util-linux.git⟩ on
       2023-12-22. (At that time, the date of the most recent commit
       that was found in the repository was 2023-12-14.) If you discover
       any rendering problems in this HTML version of the page, or you
       believe there is a better or more up-to-date source for the page,
       or you have corrections or improvements to the information in
       this COLOPHON (which is not part of the original manual page),
       send a mail to man-pages@man7.org

util-linux 2.39.1041-8a7c      2023-12-22                     FINDMNT(8)

Pages that refer to this page: eject(1)mount(2)fstab(5)mount_namespaces(7)lsblk(8)mount(8)