FINDMNT(8)

NAME
findmnt - find a filesystem

SYNOPSIS

findmnt [options]

findmnt [options] device|mountpoint

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

DESCRIPTION

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

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

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

-b, --bytes
    Print sizes in bytes rather than in human-readable form.

    By default, sizes are shown in units that are powers of 1024 bytes. The formal abbreviations for these units (KiB, MiB, GiB, ...) are further shortened to just their first letter: K, M, G, ....

-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.

-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. See also -I, --dfi options.

-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 columns that can be specified with the --output option. Can be used with --json or --raw to get the list in a machine-readable format.

--hyperlink[=when]
    Print paths as terminal hyperlinks. The optional when argument can be always, never, or auto. If the argument is omitted, it defaults to auto, which means that hyperlinks will only be used when the output goes to a terminal.

-I, --dfi
    Imitate the output of df(1) with its -i option. This option is equivalent to -o SOURCE,FSTYPE,INO.TOTAL,INO.USED,INO.AVAIL,INO.USE%,TARGET but excludes all pseudo filesystems. Use --all to print all filesystems.

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

--id number
    Select a filesystem using the mount node ID.

--uniq-id number
    Select a filesystem using the mount node 64-bit ID, use with --kernel=listmount option.

-J, --json
    Use JSON output format.

-k, --kernel[=method]
    Reads information about filesystems from the kernel. This is the default output. The format is tree-like and only includes mount options managed by the kernel (see also --mtab).

    The optional argument method is supported only for the long variant (--kernel). The short variant (-k) defaults to the mountinfo method for backward compatibility. The supported methods can be either:

        • mountinfo - this is the default method and it reads data from the /proc/self/mountinfo file.

        • listmount - This is an EXPERIMENTAL method that uses the listmount(2) and statmount(2) syscalls to generate the mount table. The output may not contain all details about mount nodes (for example, SOURCE is currently missing).

-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.

-Q, --filter expr
    Print only the filesystems that meet the conditions specified by the expr.

    This feature is EXPERIMENTAL. See also scols-filter(5). For example, include xfs having more than 50% free space:

        findmnt -Q 'INO.USED < INO.AVAIL && FSTYPE == "xfs"'

-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).

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

-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).

-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.

--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.

-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.

-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
    Display version and exit.

EXIT STATUS

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

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.

LIBSMARTCOLS_JSON=compact|lines
    Controls JSON output format when using --json. Supported values are compact for JSON output with minimal whitespace, and lines for JSON Lines format (one JSON object per line). If unset or set to any other value, pretty-printed JSON is used.

EXAMPLES

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

SEE ALSO

fstab(5), mount(8) scols-filter(5)

REPORTING BUGS

For bug reports, use the

AVAILABILITY

The findmnt command is part of the util-linux package which can be downloaded from