systemd.mountsystemdDeveloperLennartPoetteringlennart@poettering.netsystemd.mount5systemd.mountMount unit configurationmount.mountDescriptionA 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.unit5
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.exec5,
which define the execution environment the
mount8
binary is executed in, and in
systemd.kill5,
which define the way the processes are terminated, and in
systemd.resource-control5,
which configure resource control settings for the processes of the
service. 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;
mount8
will refuse options that are not 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.unit5. Note that mount
units cannot be templated, nor is possible to add multiple names to a mount unit by creating additional symlinks to
it.Optionally, a mount unit may be accompanied by an automount
unit, to allow on-demand or parallelized mounting. See
systemd.automount5.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
proc5.
Some file systems have special semantics as API file systems
for kernel-to-userspace and userspace-to-userspace interfaces. Some
of them may not be changed via mount units, and cannot be
disabled. For a longer discussion see API
File Systems.Automatic DependenciesIf a mount unit is beneath another mount unit in the file
system hierarchy, both a requirement dependency and an ordering
dependency between both units are created automatically.Block device backed file systems automatically gain
BindsTo= and After= type
dependencies on the device unit encapsulating the block
device (see below).If traditional file system quota is enabled for a mount
unit, automatic Wants= and
Before= dependencies on
systemd-quotacheck.service and
quotaon.service are added.For mount units with DefaultDependencies=yes in the [Unit] section (the
default) a couple additional dependencies are added. Mount units referring to local file systems automatically gain
an After= dependency on local-fs-pre.target. Network mount units
automatically acquire After= dependencies on remote-fs-pre.target,
network.target and network-online.target. Towards the latter a
Wants= unit is added as well. Mount units referring to local and network file systems are
distinguished by their file system type specification. In some cases this is not sufficient (for example network
block device based mounts, such as iSCSI), in which case may be added to the mount option
string of the unit, which forces systemd to consider the mount unit a network mount. Mount units (regardless if
local or network) also acquire automatic Before= and Conflicts= on
umount.target in order to be stopped during shutdown.Additional implicit dependencies may be added as result of
execution and resource control parameters as documented in
systemd.exec5
and
systemd.resource-control5.<filename>fstab</filename>Mount units may either be configured via unit files, or via
/etc/fstab (see
fstab5
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. In general,
configuring mount points through /etc/fstab
is the preferred approach. See
systemd-fstab-generator8
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. systemd will create a
dependency of type Wants= or
(see option
below), from either local-fs.target or
remote-fs.target, depending whether the file
system is local or remote.Configures a Requires= and
an After= dependency between the created
mount unit and another systemd unit, such as a device or mount
unit. The argument should be a unit name, or an absolute path
to a device node or mount point. This option may be specified
more than once. This option is particularly useful for mount
point declarations that need an additional device to be around
(such as an external journal device for journal file systems)
or an additional mount to be in place (such as an overlay file
system that merges multiple mount points). See
After= and Requires= in
systemd.unit5
for details.Configures a
RequiresMountsFor= dependency between the
created mount unit and other mount units. The argument must be
an absolute path. This option may be specified more than once.
See RequiresMountsFor= in
systemd.unit5
for details.An automount unit will be created for the file
system. See
systemd.automount5
for details.Configures the idle timeout of the
automount unit. See TimeoutIdleSec= in
systemd.automount5
for details.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 append a unit such as s,
min, h,
ms.Note that this option can only be used in
/etc/fstab, and will be
ignored when part of the Options=
setting in a unit file.With , this mount will
not be added as a dependency for
local-fs.target or
remote-fs.target. This means that it will
not be mounted automatically during boot, unless it is pulled
in by some other unit. The option has the
opposite meaning and is the default.With , this mount will
be only wanted, not required, by
local-fs.target or
remote-fs.target. This means that the
boot will continue even if this mount point is not mounted
successfully.An additional filesystem to be mounted in the
initramfs. See initrd-fs.target
description in
systemd.special7.
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.OptionsMount 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.exec5
and
systemd.kill5.
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
mount8
for details. If this refers to a device node, a dependency on
the respective device unit is automatically created. (See
systemd.device5
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 filename. (See above.) This option is
mandatory.Type=Takes a string for the file system type. See
mount8
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.SloppyOptions=Takes a boolean argument. If true, parsing of
the options specified in Options= is
relaxed, and unknown mount options are tolerated. This
corresponds with
mount8's
-s switch. Defaults to
off.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
in
systemd.kill5.)
Takes a unit-less value in seconds, or a time span value such
as "5min 20s". Pass 0 to disable the timeout logic. The
default value is set from the manager configuration file's
DefaultTimeoutStart=
variable.Check
systemd.exec5
and
systemd.kill5
for more settings.See Alsosystemd1,
systemctl1,
systemd.unit5,
systemd.exec5,
systemd.kill5,
systemd.resource-control5,
systemd.service5,
systemd.device5,
proc5,
mount8,
systemd-fstab-generator8,
systemd.directives7