systemd.mount — Mount unit configuration
mount.mount
A unit configuration file whose name ends in
.mount encodes information about
a file system mount point controlled and supervised by
systemd.
This man page lists the configuration options specific to this unit type. See systemd.unit(5) for the common options of all unit configuration files. The common configuration items are configured in the generic [Unit] and [Install] sections. The mount specific configuration options are configured in the [Mount] section.
Additional options are listed in
systemd.exec(5),
which define the execution environment the
mount(8)
binary is executed in, and in
systemd.kill(5)
which define the way the processes are
terminated. Note that the User= and Group= options are
not particularly useful for mount units specifying a
Type= option or using configuration
not specified in /etc/fstab;
mount(8)
will refuse options that aren't listed in
/etc/fstab if it is not run as
UID 0.
Mount units must be named after the mount point
directories they control. Example: the mount point
/home/lennart must be configured
in a unit file
home-lennart.mount. For details
about the escaping logic used to convert a file system
path to a unit name see
systemd.unit(5).
Optionally, a mount unit may be accompanied by an automount unit, to allow on-demand or parallelized mounting. See systemd.automount(5).
If a mount point is beneath another mount point in the file system hierarchy, a dependency between both units is created automatically.
Mount points created at runtime (independently of
unit files or /etc/fstab) will be
monitored by systemd and appear like any other mount
unit in systemd.
See /proc/self/mountinfo description
in proc(5).
Some file systems have special semantics as API file systems for kernel-to-userspace and userspace-to-userpace interfaces. Some of them may not be changed via mount units, and cannot be disabled. For a longer discussion see API File Systems.
/etc/fstab¶Mount units may either be configured via unit
files, or via /etc/fstab (see
fstab(5)
for details). Mounts listed in
/etc/fstab will be converted into
native units dynamically at boot and when the
configuration of the system manager is reloaded. See
systemd-fstab-generator(8)
for details about the conversion.
When reading /etc/fstab a
few special mount options are understood by systemd
which influence how dependencies are created for mount
points from /etc/fstab. systemd
will create a dependency of type
Wants from either
local-fs.target or
remote-fs.target, depending
whether the file system is local or remote. If
x-systemd.automount is set, an
automount unit will be created for the file
system. See
systemd.automount(5)
for details. If
x-systemd.device-timeout= is
specified it may be used to configure how long systemd
should wait for a device to show up before giving up
on an entry from
/etc/fstab. Specify a time in
seconds or explicitly specify a unit as
s, min,
h, ms.
If a mount point is configured in both
/etc/fstab and a unit file that
is stored below /usr the former
will take precedence. If the unit file is stored below
/etc it will take
precedence. This means: native unit files take
precedence over traditional configuration files, but
this is superseded by the rule that configuration in
/etc will always take precedence
over configuration in
/usr.
Mount files must include a [Mount] section, which carries information about the file system mount points it supervises. A number of options that may be used in this section are shared with other unit types. These options are documented in systemd.exec(5) and systemd.kill(5). The options specific to the [Mount] section of mount units are the following:
What=¶Takes an absolute path of a device node, file or other resource to mount. See mount(8) for details. If this refers to a device node, a dependency on the respective device unit is automatically created. (See systemd.device(5) for more information.) This option is mandatory.
Where=¶Takes an absolute path of a directory of the mount point. If the mount point does not exist at the time of mounting, it is created. This string must be reflected in the unit file name. (See above.) This option is mandatory.
Type=¶Takes a string for the filesystem type. See mount(8) for details. This setting is optional.
Options=¶Mount options to use when mounting. This takes a comma separated list of options. This setting is optional.
DirectoryMode=¶Directories of mount points (and any parent directories) are automatically created if needed. This option specifies the file system access mode used when creating these directories. Takes an access mode in octal notation. Defaults to 0755.
TimeoutSec=¶Configures the time to
wait for the mount command to
finish. If a command does not exit
within the configured time the mount
will be considered failed and be shut
down again. All commands still running
will be terminated forcibly via
SIGTERM, and after another delay of
this time with SIGKILL. (See
KillMode= in
systemd.kill(5).)
Takes a unit-less value in seconds, or
a time span value such as "5min
20s". Pass 0 to disable the timeout
logic. Defaults to
90s.
Check systemd.exec(5) and systemd.kill(5) for more settings.
The following option is also available in the
[Mount] section, but exists purely
for compatibility reasons and should not be used in
newly written mount files.
FsckPassNo=¶The pass number for the file system checking service for this mount. See systemd.service(5) for more information on this setting.