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7 This file is part of systemd.
9 Copyright 2010 Lennart Poettering
11 systemd is free software; you can redistribute it and/or modify it
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25 <refentry id="systemd.mount">
27 <title>systemd.mount</title>
28 <productname>systemd</productname>
32 <contrib>Developer</contrib>
33 <firstname>Lennart</firstname>
34 <surname>Poettering</surname>
35 <email>lennart@poettering.net</email>
41 <refentrytitle>systemd.mount</refentrytitle>
42 <manvolnum>5</manvolnum>
46 <refname>systemd.mount</refname>
47 <refpurpose>Mount unit configuration</refpurpose>
51 <para><filename><replaceable>mount</replaceable>.mount</filename></para>
55 <title>Description</title>
57 <para>A unit configuration file whose name ends in
58 <literal>.mount</literal> encodes information about
59 a file system mount point controlled and supervised by
62 <para>This man page lists the configuration options
63 specific to this unit type. See
64 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
65 for the common options of all unit configuration
66 files. The common configuration items are configured
67 in the generic [Unit] and [Install] sections. The
68 mount specific configuration options are configured
69 in the [Mount] section.</para>
71 <para>Additional options are listed in
72 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
73 which define the execution environment the
74 <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>
75 binary is executed in, and in
76 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
77 which define the way the processes are terminated, and
79 <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
80 which configure resource control settings for the
81 processes of the service. Note that the User= and
82 Group= options are not particularly useful for mount
83 units specifying a <literal>Type=</literal> option or
84 using configuration not specified in
85 <filename>/etc/fstab</filename>;
86 <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>
87 will refuse options that are not listed in
88 <filename>/etc/fstab</filename> if it is not run as
91 <para>Mount units must be named after the mount point
92 directories they control. Example: the mount point
93 <filename noindex='true'>/home/lennart</filename> must be configured
95 <filename>home-lennart.mount</filename>. For details
96 about the escaping logic used to convert a file system
97 path to a unit name, see
98 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
100 <para>Optionally, a mount unit may be accompanied by
101 an automount unit, to allow on-demand or parallelized
103 <citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
105 <para>If a mount point is beneath another mount point
106 in the file system hierarchy, a dependency between both
107 units is created automatically.</para>
109 <para>Mount points created at runtime (independently of
110 unit files or <filename>/etc/fstab</filename>) will be
111 monitored by systemd and appear like any other mount
113 See <filename>/proc/self/mountinfo</filename> description
114 in <citerefentry><refentrytitle>proc</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
117 <para>Some file systems have special semantics as API
118 file systems for kernel-to-userspace and
119 userspace-to-userpace interfaces. Some of them may not
120 be changed via mount units, and cannot be disabled.
121 For a longer discussion see <ulink
122 url="http://www.freedesktop.org/wiki/Software/systemd/APIFileSystems">API
123 File Systems</ulink>.</para>
127 <title><filename>/etc/fstab</filename></title>
129 <para>Mount units may either be configured via unit
130 files, or via <filename>/etc/fstab</filename> (see
131 <citerefentry><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>
132 for details). Mounts listed in
133 <filename>/etc/fstab</filename> will be converted into
134 native units dynamically at boot and when the
135 configuration of the system manager is reloaded. In
136 general, configuring mount points through
137 <filename>/etc/fstab</filename> is the preferred
139 <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
140 for details about the conversion.</para>
142 <para>When reading <filename>/etc/fstab</filename> a
143 few special mount options are understood by systemd
144 which influence how dependencies are created for mount
145 points from <filename>/etc/fstab</filename>. systemd
146 will create a dependency of type
147 <option>Wants</option> from either
148 <filename>local-fs.target</filename> or
149 <filename>remote-fs.target</filename>, depending
150 whether the file system is local or remote. If
151 <option>x-systemd.automount</option> is set, an
152 automount unit will be created for the file
154 <citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
156 <option>x-systemd.device-timeout=</option> is
157 specified, it may be used to configure how long systemd
158 should wait for a device to show up before giving up
160 <filename>/etc/fstab</filename>. Specify a time in
161 seconds or explicitly specify a unit as
162 <literal>s</literal>, <literal>min</literal>,
163 <literal>h</literal>, <literal>ms</literal>.</para>
165 <para>If <option>nofail</option> is given, this mount
166 will be only wanted, not required, by the
167 <filename>local-fs.target</filename>. This means that
168 the boot will continue even if this mount point is not
169 mounted successfully. Option <option>fail</option> has
170 the opposite meaning and is the default.</para>
172 <para>If <option>noauto</option> is given, this mount
173 will not be added as a dependency for
174 <filename>local-fs.target</filename>. This means that
175 it will not be mounted automatically during boot,
176 unless it is pulled in by some other unit. Option
177 <option>auto</option> has the opposite meaning and is
180 <para>If a mount point is configured in both
181 <filename>/etc/fstab</filename> and a unit file that
182 is stored below <filename>/usr</filename>, the former
183 will take precedence. If the unit file is stored below
184 <filename>/etc</filename>, it will take
185 precedence. This means: native unit files take
186 precedence over traditional configuration files, but
187 this is superseded by the rule that configuration in
188 <filename>/etc</filename> will always take precedence
189 over configuration in
190 <filename>/usr</filename>.</para>
194 <title>Options</title>
196 <para>Mount files must include a [Mount] section,
197 which carries information about the file system mount points it
198 supervises. A number of options that may be used in
199 this section are shared with other unit types. These
200 options are documented in
201 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
203 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>. The
204 options specific to the [Mount] section of mount
205 units are the following:</para>
207 <variablelist class='unit-directives'>
210 <term><varname>What=</varname></term>
211 <listitem><para>Takes an absolute path
212 of a device node, file or other
213 resource to mount. See
214 <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>
215 for details. If this refers to a
216 device node, a dependency on the
217 respective device unit is
218 automatically created. (See
219 <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry> for more information.)
221 mandatory.</para></listitem>
225 <term><varname>Where=</varname></term>
226 <listitem><para>Takes an absolute path
227 of a directory of the mount point. If
228 the mount point does not exist at the
229 time of mounting, it is created. This
230 string must be reflected in the unit
231 filename. (See above.) This option is
232 mandatory.</para></listitem>
236 <term><varname>Type=</varname></term>
237 <listitem><para>Takes a string for the
238 file system type. See
239 <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>
240 for details. This setting is
241 optional.</para></listitem>
245 <term><varname>Options=</varname></term>
247 <listitem><para>Mount options to use
248 when mounting. This takes a
249 comma-separated list of options. This
250 setting is optional.</para></listitem>
254 <term><varname>SloppyOptions=</varname></term>
256 <listitem><para>Takes a boolean
257 argument. If true parsing of the
259 <varname>Options=</varname> is
260 relaxed, and unknown mount options are
261 tolerated. This corresponds with
262 <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>'s
263 <parameter>-s</parameter>
265 off.</para></listitem>
269 <term><varname>DirectoryMode=</varname></term>
270 <listitem><para>Directories of mount
271 points (and any parent directories)
272 are automatically created if
273 needed. This option specifies the file
274 system access mode used when creating
275 these directories. Takes an access
276 mode in octal notation. Defaults to
277 0755.</para></listitem>
281 <term><varname>TimeoutSec=</varname></term>
282 <listitem><para>Configures the time to
283 wait for the mount command to
284 finish. If a command does not exit
285 within the configured time, the mount
286 will be considered failed and be shut
287 down again. All commands still running
288 will be terminated forcibly via
289 <constant>SIGTERM</constant>, and after another delay of
290 this time with <constant>SIGKILL</constant>. (See
291 <option>KillMode=</option> in
292 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>.)
293 Takes a unit-less value in seconds, or
294 a time span value such as "5min
295 20s". Pass 0 to disable the timeout
296 logic. The default value is set from the manager configuration
297 file's <varname>DefaultTimeoutStart=</varname> variable.</para></listitem>
302 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
304 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>
305 for more settings.</para>
309 <title>See Also</title>
311 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
312 <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
313 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
314 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
315 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
316 <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
317 <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
318 <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
319 <citerefentry><refentrytitle>proc</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
320 <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
321 <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
322 <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>