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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
12 under the terms of the GNU General Public License as published by
13 the Free Software Foundation; either version 2 of the License, or
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19 General Public License for more details.
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25 <refentry id="systemd.swap">
27 <title>systemd.swap</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.swap</refentrytitle>
42 <manvolnum>5</manvolnum>
46 <refname>systemd.swap</refname>
47 <refpurpose>systemd swap configuration files</refpurpose>
51 <para><filename>systemd.swap</filename></para>
55 <title>Description</title>
57 <para>A unit configuration file whose name ends in
58 <filename>.swap</filename> encodes information about a
59 swap device or file for memory paging controlled and
60 supervised by systemd.</para>
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 swap
68 specific configuration options are configured in the
69 [Swap] section.</para>
71 <para>Swap units must be named after the devices they
72 control. Example: the swap device
73 <filename>/dev/sda5</filename> must be configured in a
74 unit file <filename>dev-sda5.swap</filename>. For
75 details about the escaping logic used to convert a
76 file system path to a unit name see
77 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
81 <title><filename>fstab</filename></title>
83 <para>Swap units may either be configured via unit
84 files, or via <filename>/etc/fstab</filename> (see
85 <citerefentry><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>
88 <para>If a swap device or file is configured in both
89 <filename>/etc/fstab</filename> and a unit file the
90 configuration in the latter takes precedence.</para>
94 <title>Options</title>
96 <para>Swap files must include a [Swap] section, which
97 carries information about the swap device it
98 supervises. A number of options that may be used in
99 this section are shared with other unit types. These
100 options are documented in
101 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>. The
102 options specific to the [Swap] section of swap units
103 are the following:</para>
108 <term><varname>What=</varname></term>
109 <listitem><para>Takes an absolute path
110 of a device node or file to use for
112 <citerefentry><refentrytitle>swapon</refentrytitle><manvolnum>8</manvolnum></citerefentry>
113 for details. If this refers to a
114 device node, a dependency on the
115 respective device unit is
116 automatically created. (See
117 <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>
118 for more information.) If this refers
119 to a file, a dependency on the
120 respective mount unit is automatically
122 <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
123 for more information.) This option is
124 mandatory.</para></listitem>
128 <term><varname>Priority=</varname></term>
130 <listitem><para>Swap priority to use
131 when activating the swap device or
132 file. This takes an integer. This
133 setting is optional.</para></listitem>
137 <term><varname>TimeoutSec=</varname></term>
138 <listitem><para>Configures the time to
139 wait for the swapon command to
140 finish. If a command does not exit
141 within the configured time the swap
142 will be considered failed and be shut
143 down again. All commands still running
144 will be terminated forcibly via
145 SIGTERM, and after another delay of
146 this time with SIGKILL. (See
147 <option>KillMode=</option> below.)
148 Takes a unit-less value in seconds, or
149 a time span value such as "5min
150 20s". Pass 0 to disable the timeout
152 60s.</para></listitem>
156 <term><varname>KillMode=</varname></term>
157 <listitem><para>Specifies how
158 processes of this swap shall be
160 <option>control-group</option>,
161 <option>process-group</option>,
162 <option>process</option>,
163 <option>none</option>.</para>
165 <para>This option is mostly equivalent
166 to the <option>KillMode=</option>
167 option of service files. See
168 <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
169 for details.</para></listitem>
173 <term><varname>KillSignal=</varname></term>
174 <listitem><para>Specifies which signal
175 to use when killing a process of this
176 swap. Defaults to SIGTERM.
181 <term><varname>SendSIGKILL=</varname></term>
182 <listitem><para>Specifies whether to
183 send SIGKILL to remaining processes
184 after a timeout, if the normal
185 shutdown procedure left processes of
186 the swap around. Takes a boolean
187 value. Defaults to "yes".
194 <title>See Also</title>
196 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
197 <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
198 <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
199 <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
200 <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
201 <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
202 <citerefentry><refentrytitle>swapon</refentrytitle><manvolnum>8</manvolnum></citerefentry>