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7 This file is part of systemd.
9 Copyright 2010 Lennart Poettering
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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 <filename>.mount</filename> 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
78 terminated. Note that the User= and Group= options are
79 not particularly useful for mount units specifying a
80 <literal>Type=</literal> option or using configuration
81 not specified in <filename>/etc/fstab</filename>;
82 <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>
83 will refuse options that aren't listed in
84 <filename>/etc/fstab</filename> if it is not run as
87 <para>Mount units must be named after the mount point
88 directories they control. Example: the mount point
89 <filename noindex='true'>/home/lennart</filename> must be configured
91 <filename>home-lennart.mount</filename>. For details
92 about the escaping logic used to convert a file system
93 path to a unit name see
94 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
96 <para>Optionally, a mount unit may be accompanied by
97 an automount unit, to allow on-demand or parallelized
99 <citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
101 <para>If a mount point is beneath another mount point
102 in the file system hierarchy, a dependency between both
103 units is created automatically.</para>
105 <para>Mount points created at runtime (independently of
106 unit files or <filename>/etc/fstab</filename>) will be
107 monitored by systemd and appear like any other mount
109 See <filename>/proc/self/mountinfo</filename> description
110 in <citerefentry><refentrytitle>proc</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
113 <para>Some file systems have special semantics as API
114 file systems for kernel-to-userspace and
115 userspace-to-userpace interfaces. Some of them may not
116 be changed via mount units, and cannot be disabled.
117 For a longer discussion see <ulink
118 url="http://www.freedesktop.org/wiki/Software/systemd/APIFileSystems">API
119 File Systems</ulink>.</para>
123 <title><filename>/etc/fstab</filename></title>
125 <para>Mount units may either be configured via unit
126 files, or via <filename>/etc/fstab</filename> (see
127 <citerefentry><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>
128 for details). Mounts listed in
129 <filename>/etc/fstab</filename> will be converted into
130 native units dynamically at boot and when the
131 configuration of the system manager is reloaded. See
132 <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
133 for details about the conversion.</para>
135 <para>When reading <filename>/etc/fstab</filename> a
136 few special mount options are understood by systemd
137 which influence how dependencies are created for mount
138 points from <filename>/etc/fstab</filename>. systemd
139 will create a dependency of type
140 <option>Wants</option> from either
141 <filename>local-fs.target</filename> or
142 <filename>remote-fs.target</filename>, depending
143 whether the file system is local or remote. If
144 <option>x-systemd.automount</option> is set, an
145 automount unit will be created for the file
147 <citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
149 <option>x-systemd.device-timeout=</option> is
150 specified it may be used to configure how long systemd
151 should wait for a device to show up before giving up
153 <filename>/etc/fstab</filename>. Specify a time in
154 seconds or explicitly specify a unit as
155 <literal>s</literal>, <literal>min</literal>,
156 <literal>h</literal>, <literal>ms</literal>.</para>
158 <para>If a mount point is configured in both
159 <filename>/etc/fstab</filename> and a unit file that
160 is stored below <filename>/usr</filename> the former
161 will take precedence. If the unit file is stored below
162 <filename>/etc</filename> it will take
163 precedence. This means: native unit files take
164 precedence over traditional configuration files, but
165 this is superseded by the rule that configuration in
166 <filename>/etc</filename> will always take precedence
167 over configuration in
168 <filename>/usr</filename>.</para>
172 <title>Options</title>
174 <para>Mount files must include a [Mount] section,
175 which carries information about the file system mount points it
176 supervises. A number of options that may be used in
177 this section are shared with other unit types. These
178 options are documented in
179 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
181 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>. The
182 options specific to the [Mount] section of mount
183 units are the following:</para>
185 <variablelist class='unit-directives'>
188 <term><varname>What=</varname></term>
189 <listitem><para>Takes an absolute path
190 of a device node, file or other
191 resource to mount. See
192 <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>
193 for details. If this refers to a
194 device node, a dependency on the
195 respective device unit is
196 automatically created. (See
197 <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry> for more information.)
199 mandatory.</para></listitem>
203 <term><varname>Where=</varname></term>
204 <listitem><para>Takes an absolute path
205 of a directory of the mount point. If
206 the mount point does not exist at the
207 time of mounting, it is created. This
208 string must be reflected in the unit
209 filename. (See above.) This option is
210 mandatory.</para></listitem>
214 <term><varname>Type=</varname></term>
215 <listitem><para>Takes a string for the
216 file system type. See
217 <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>
218 for details. This setting is
219 optional.</para></listitem>
223 <term><varname>Options=</varname></term>
225 <listitem><para>Mount options to use
226 when mounting. This takes a
227 comma-separated list of options. This
228 setting is optional.</para></listitem>
232 <term><varname>DirectoryMode=</varname></term>
233 <listitem><para>Directories of mount
234 points (and any parent directories)
235 are automatically created if
236 needed. This option specifies the file
237 system access mode used when creating
238 these directories. Takes an access
239 mode in octal notation. Defaults to
240 0755.</para></listitem>
244 <term><varname>TimeoutSec=</varname></term>
245 <listitem><para>Configures the time to
246 wait for the mount command to
247 finish. If a command does not exit
248 within the configured time, the mount
249 will be considered failed and be shut
250 down again. All commands still running
251 will be terminated forcibly via
252 SIGTERM, and after another delay of
253 this time with SIGKILL. (See
254 <option>KillMode=</option> in
255 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>.)
256 Takes a unit-less value in seconds, or
257 a time span value such as "5min
258 20s". Pass 0 to disable the timeout
260 90s.</para></listitem>
265 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
267 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>
268 for more settings.</para>
272 <title>Compatibility Options</title>
274 <para>The following option is also available in the
275 <literal>[Mount]</literal> section, but exists purely
276 for compatibility reasons and should not be used in
277 newly written mount files.</para>
279 <variablelist class='unit-directives'>
281 <term><varname>FsckPassNo=</varname></term>
283 <listitem><para>The pass number for
284 the file system checking service for
286 <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
287 for more information on this setting.
294 <title>See Also</title>
296 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
297 <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
298 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
299 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
300 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
301 <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
302 <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
303 <citerefentry><refentrytitle>proc</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
304 <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
305 <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
306 <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>