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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>systemd.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>/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
108 unit in systemd.</para>
110 <para>Some file systems have special semantics as API
111 file systems for kernel-to-userspace and
112 userspace-to-userpace interfaces. Some of them may not
113 be changed via mount units, and cannot be disabled.
114 For a longer discussion see <ulink
115 url="http://www.freedesktop.org/wiki/Software/systemd/APIFileSystems">API
116 File Systems</ulink>.</para>
120 <title><filename>/etc/fstab</filename></title>
122 <para>Mount units may either be configured via unit
123 files, or via <filename>/etc/fstab</filename> (see
124 <citerefentry><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>
125 for details). Mounts listed in
126 <filename>/etc/fstab</filename> will be converted into
127 native units dynamically at boot and when the
128 configuration of the system manager is reloaded. See
129 <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
130 for details about the conversion.</para>
132 <para>When reading <filename>/etc/fstab</filename> a
133 few special mount options are understood by systemd
134 which influence how dependencies are created for mount
135 points from <filename>/etc/fstab</filename>. systemd
136 will create a dependency of type
137 <option>Wants</option> from either
138 <filename>local-fs.target</filename> or
139 <filename>remote-fs.target</filename>, depending
140 whether the file system is local or remote. If
141 <option>x-systemd.automount</option> is set, an
142 automount unit will be created for the file
144 <citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
146 <option>x-systemd.device-timeout=</option> is
147 specified it may be used to configure how long systemd
148 should wait for a device to show up before giving up
150 <filename>/etc/fstab</filename>. Specify a time in
151 seconds or explicitly specify a unit as
152 <literal>s</literal>, <literal>min</literal>,
153 <literal>h</literal>, <literal>ms</literal>.</para>
155 <para>If a mount point is configured in both
156 <filename>/etc/fstab</filename> and a unit file, the
157 configuration in the latter takes precedence.</para>
161 <title>Options</title>
163 <para>Mount files must include a [Mount] section,
164 which carries information about the file system mount points it
165 supervises. A number of options that may be used in
166 this section are shared with other unit types. These
167 options are documented in
168 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
170 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>. The
171 options specific to the [Mount] section of mount
172 units are the following:</para>
177 <term><varname>What=</varname></term>
178 <listitem><para>Takes an absolute path
179 of a device node, file or other
180 resource to mount. See
181 <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>
182 for details. If this refers to a
183 device node, a dependency on the
184 respective device unit is
185 automatically created. (See
186 <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry> for more information.)
188 mandatory.</para></listitem>
192 <term><varname>Where=</varname></term>
193 <listitem><para>Takes an absolute path
194 of a directory of the mount point. If
195 the mount point does not exist at the
196 time of mounting, it is created. This
197 string must be reflected in the unit
198 file name. (See above.) This option is
199 mandatory.</para></listitem>
203 <term><varname>Type=</varname></term>
204 <listitem><para>Takes a string for the
206 <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>
207 for details. This setting is
208 optional.</para></listitem>
212 <term><varname>Options=</varname></term>
214 <listitem><para>Mount options to use
215 when mounting. This takes a comma
216 separated list of options. This
217 setting is optional.</para></listitem>
221 <term><varname>DirectoryMode=</varname></term>
222 <listitem><para>Directories of mount
223 points (and any parent directories)
224 are automatically created if
225 needed. This option specifies the file
226 system access mode used when creating
227 these directories. Takes an access
228 mode in octal notation. Defaults to
229 0755.</para></listitem>
233 <term><varname>TimeoutSec=</varname></term>
234 <listitem><para>Configures the time to
235 wait for the mount command to
236 finish. If a command does not exit
237 within the configured time the mount
238 will be considered failed and be shut
239 down again. All commands still running
240 will be terminated forcibly via
241 SIGTERM, and after another delay of
242 this time with SIGKILL. (See
243 <option>KillMode=</option> in
244 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>.)
245 Takes a unit-less value in seconds, or
246 a time span value such as "5min
247 20s". Pass 0 to disable the timeout
249 90s.</para></listitem>
254 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
256 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>
257 for more settings.</para>
261 <title>Compatibility Options</title>
263 <para>The following option is also available in the
264 <literal>[Mount]</literal> section, but exists purely
265 for compatibility reasons and should not be used in
266 newly written mount files.</para>
270 <term><varname>FsckPassNo=</varname></term>
272 <listitem><para>The pass number for
273 the file system checking service for
275 <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
276 for more information on this setting.
283 <title>See Also</title>
285 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
286 <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
287 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
288 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
289 <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
290 <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
291 <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
292 <citerefentry><refentrytitle>mount</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
293 <citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>