#Bash 的 findmnt 命令
findmnt [OPTIONS]
功能
查询文件系统及挂载点。
类型
可执行文件（/usr/bin/findmnt），属于 util-linux。
参数
OPTIONS选项：-
-A, --all禁用所有内置过滤器，显示所有文件系统。 -
-a, --ascii使用 ASCII 字符显示树状格式。 -
-b, --bytes以字节为单位显示文件系统大小，而不是人类可读格式。 默认单位是字节，前缀以 2^10 为基数（KiB、MiB 等）。为了可读性，符号缩写会只显示首字母，例如 “1 KiB” 显示为 “1 K”，省略了 “iB”。 -
-C, --nocanonicalize不进行路径规范化。此选项影响路径比较和标签（LABEL、UUID 等）的解析。 -
-c, --canonicalize对所有输出路径进行规范化。 -
--deleted显示内核标记为已删除的挂载目标（mountpoint）的文件系统。 -
-D, --df模拟df(1)输出。等价于-o SOURCE,FSTYPE,SIZE,USED,AVAIL,USE%,TARGET，但排除伪文件系统。使用--all可以显示所有文件系统。 -
-d, --direction word搜索方向，可选值为 forward（向前）或 backward（向后）。 -
-e, --evaluate将所有标签（LABEL、UUID、PARTUUID、PARTLABEL）转换为 SOURCE 列对应的设备名。可能存在标签重复的情况，此时会显示 SOURCES 列（多行显示所有匹配设备）。此选项主要对fstab有意义。 -
-F, --tab-file path指定替代挂载表文件。如果与--fstab、--mtab或--kernel一起使用，则覆盖默认路径。指定多次会禁用树状输出（改为列表模式）。 -
-f, --first-only只显示第一个匹配的文件系统。 -
-i, --invert反转匹配逻辑（显示不匹配的项）。 -
-J, --json使用 JSON 格式输出。 -
-k, --kernel在/proc/self/mountinfo中搜索。输出为树状格式，默认选项，仅显示内核维护的挂载选项（参见--mtab）。 -
-l, --list使用列表格式输出。当输出受-t、-O、-S、-T限制且未使用--submounts，或指定多个-F文件时，自动启用列表格式。 -
-M, --mountpoint path明确指定挂载点文件或目录。可与--target互换使用。 -
-m, --mtab在/etc/mtab中搜索。默认输出列表格式，可能包含用户空间挂载选项。 -
-N, --task tid使用替代命名空间/proc/<tid>/mountinfo而非默认/proc/self/mountinfo。指定多次会禁用树状输出。参考unshare(1)。 -
-n, --noheadings不显示表头行。 -
-O, --options list限制输出的文件系统选项。多个选项用逗号分隔，-t 与 -O 可以叠加。每个选项精确匹配，可在单个选项前加no表示排除。+前缀可禁用no解释。 -
-o, --output list自定义输出列。列名可通过--help查看。默认 TARGET 列会显示树状格式（除非使用--list或--raw）。可用+列名扩展默认列。 -
--output-all输出几乎所有可用列，排除需要--poll的列。 -
-P, --pairs以key="value"形式输出，值中的特殊字符以十六进制转义。可与--shell配合使用。 -
-p, --poll[=list]监控/proc/self/mountinfo的变化，支持动作：mount、umount、remount、move。动作可用逗号分隔，默认监控所有动作。可配合--timeout或--first-only限制阻塞时间。 -
--pseudo仅显示伪文件系统。 -
--shadow仅显示被其他文件系统覆盖的挂载点。 -
-R, --submounts递归显示选中文件系统的子挂载点。子挂载点总是树状输出。对--mtab或--fstab无效。 -
-r, --raw使用原始格式输出，所有潜在危险字符以十六进制转义。 -
--real仅显示真实文件系统。 -
-S, --source spec明确指定挂载源，可用 device、maj:min、LABEL、UUID、PARTLABEL、PARTUUID 等。 -
-s, --fstab在/etc/fstab中搜索，列表格式输出。 -
-T, --target path指定挂载目标路径。如果不是挂载点，会反向检查路径元素获取挂载点（仅支持 kernel 搜索，不支持 fstab）。 -
-t, --types list限制输出的文件系统类型，可用no前缀排除类型。 -
--tree启用树状输出（仅当存在父子关系时有效，fstab 等可能被忽略）。 -
--shadowed仅显示被覆盖的挂载点（同--shadow）。 -
-U, --uniq忽略重复挂载目标的文件系统（跳过被覆盖挂载点）。 -
-u, --notruncate不截断列文本。默认只截断非 TARGET、SOURCE、UUID、LABEL、PARTUUID、PARTLABEL 列。 -
-v, --nofsroot对 bind mount 或 btrfs 子卷，SOURCE 列不显示 [/dir]。 -
-w, --timeout milliseconds指定--poll阻塞时间上限（毫秒）。 -
-x, --verify检查挂载表内容。默认验证/etc/fstab可解析性，可与--tab-file一起使用。可指定源或目标过滤，--verbose可显示详细信息。 -
--verbose强制显示更多信息（当前仅对--verify有效）。 -
--vfs-all当与 VFS-OPTIONS 列一起使用时，显示所有 VFS（与文件系统无关）标志，用于审计，显示默认内核挂载选项。 -
-y, --shell将列名修改为仅包含 shell 变量允许的字符，可与--pairs配合使用。 -
--help- 显示帮助 -
--version- 显示版本
-
#示例
$ findmnt
TARGET SOURCE FSTYPE OPTIONS
/ /dev/nvme0n1p2
ext4 rw,relatime
├─/sys sysfs sysfs rw,nosuid,nodev,noexec,relatime
│ ├─/sys/firmware/efi/efivars efivarfs
│ │ efivarfs rw,nosuid,nodev,noexec,relatime
│ ├─/sys/kernel/security securityfs
│ │ securityfs rw,nosuid,nodev,noexec,relatime
│ ├─/sys/fs/cgroup cgroup2
...
#推荐阅读
#手册
FINDMNT(8) System Administration 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 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.
-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.
-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>).
--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
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.
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
Karel Zak <[email protected]>
SEE ALSO
fstab(5), mount(8)
REPORTING BUGS
For bug reports, use the issue tracker at
https://github.com/util-linux/util-linux/issues.
AVAILABILITY
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/>.
util-linux 2.39.3 2023-12-01 FINDMNT(8)