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<refentry id="systemd.swap">

<refentryinfo>

<title>systemd.swap</title>

<productname>systemd</productname>

<authorgroup>

<author>

<contrib>Developer</contrib>

<firstname>Lennart</firstname>

<surname>Poettering</surname>

<email>lennart@poettering.net</email>

</author>

</authorgroup>

</refentryinfo>

<refmeta>

<refentrytitle>systemd.swap</refentrytitle>

<manvolnum>5</manvolnum>

</refmeta>

<refnamediv>

<refname>systemd.swap</refname>

<refpurpose>systemd swap configuration files</refpurpose>

</refnamediv>

<refsynopsisdiv>

<para><filename>systemd.swap</filename></para>

</refsynopsisdiv>

<refsect1>

<title>Description</title>

<para>A unit configuration file whose name ends in

<filename>.swap</filename> encodes information about a

swap device or file for memory paging controlled and

supervised by systemd.</para>

<para>This man page lists the configuration options

specific to this unit type. See

<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>

for the common options of all unit configuration

files. The common configuration items are configured

in the generic [Unit] and [Install] sections. The swap

specific configuration options are configured in the

[Swap] section.</para>

<para>Swap units must be named after the devices they

control. Example: the swap device

<filename>/dev/sda5</filename> must be configured in a

unit file <filename>dev-sda5.swap</filename>. For

details about the escaping logic used to convert a

file system path to a unit name see

<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>

</refsect1>

<refsect1>

<title><filename>fstab</filename></title>

<para>Swap units may either be configured via unit

files, or via <filename>/etc/fstab</filename> (see

<citerefentry><refentrytitle>fstab</refentrytitle><manvolnum>5</manvolnum></citerefentry>

for details).</para>

<para>If a swap device or file is configured in both

<filename>/etc/fstab</filename> and a unit file the

configuration in the latter takes precedence.</para>

</refsect1>

<refsect1>

<title>Options</title>

<para>Swap files must include a [Swap] section, which

carries information about the swap device it

supervises. The options specific to the [Swap] section

of swap units are the following:</para>

<variablelist>

<varlistentry>

<term><varname>What=</varname></term>

<listitem><para>Takes an absolute path

of a device node or file to use for

paging. See

<citerefentry><refentrytitle>swapon</refentrytitle><manvolnum>8</manvolnum></citerefentry>

for details. If this refers to a

device node, a dependency on the

respective device unit is

automatically created. (See

<citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>

for more information.) If this refers

to a file, a dependency on the

respective mount unit is automatically

created. (See

<citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>

for more information.) This option is

mandatory.</para></listitem>

</varlistentry>

<varlistentry>

<term><varname>Priority=</varname></term>

<listitem><para>Swap priority to use

when activating the swap device or

file. This takes an integer. This

setting is optional.</para></listitem>

</varlistentry>

</variablelist>

</refsect1>

<refsect1>

<title>See Also</title>

<para>

<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,

<citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,

<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,

<citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>,

<citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,

<citerefentry><refentrytitle>swapon</refentrytitle><manvolnum>8</manvolnum></citerefentry>

</para>

</refsect1>

</refentry>