man/systemd.swap.xml

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   9   Copyright 2010 Lennart Poettering
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  24
  25 <refentry id="systemd.swap">
  26         <refentryinfo>
  27                 <title>systemd.swap</title>
  28                 <productname>systemd</productname>
  29
  30                 <authorgroup>
  31                         <author>
  32                                 <contrib>Developer</contrib>
  33                                 <firstname>Lennart</firstname>
  34                                 <surname>Poettering</surname>
  35                                 <email>lennart@poettering.net</email>
  36                         </author>
  37                 </authorgroup>
  38         </refentryinfo>
  39
  40         <refmeta>
  41                 <refentrytitle>systemd.swap</refentrytitle>
  42                 <manvolnum>5</manvolnum>
  43         </refmeta>
  44
  45         <refnamediv>
  46                 <refname>systemd.swap</refname>
  47                 <refpurpose>systemd swap configuration files</refpurpose>
  48         </refnamediv>
  49
  50         <refsynopsisdiv>
  51                 <para><filename>systemd.swap</filename></para>
  52         </refsynopsisdiv>
  53
  54         <refsect1>
  55                 <title>Description</title>
  56
  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>
  61
  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>
  70
  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>
  78         </refsect1>
  79
  80         <refsect1>
  81                 <title><filename>fstab</filename></title>
  82
  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>
  86                 for details).</para>
  87
  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>
  91         </refsect1>
  92
  93         <refsect1>
  94                 <title>Options</title>
  95
  96                 <para>Swap files must include a [Swap] section, which
  97                 carries information about the swap device it
  98                 supervises. The options specific to the [Swap] section
  99                 of swap units are the following:</para>
 100
 101                 <variablelist>
 102
 103                         <varlistentry>
 104                                 <term><varname>What=</varname></term>
 105                                 <listitem><para>Takes an absolute path
 106                                 of a device node or file to use for
 107                                 paging. See
 108                                 <citerefentry><refentrytitle>swapon</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 109                                 for details. If this refers to a
 110                                 device node, a dependency on the
 111                                 respective device unit is
 112                                 automatically created. (See
 113                                 <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 114                                 for more information.) If this refers
 115                                 to a file, a dependency on the
 116                                 respective mount unit is automatically
 117                                 created. (See
 118                                 <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 119                                 for more information.) This option is
 120                                 mandatory.</para></listitem>
 121                         </varlistentry>
 122
 123                         <varlistentry>
 124                                 <term><varname>Priority=</varname></term>
 125
 126                                 <listitem><para>Swap priority to use
 127                                 when activating the swap device or
 128                                 file. This takes an integer. This
 129                                 setting is optional.</para></listitem>
 130                         </varlistentry>
 131                 </variablelist>
 132         </refsect1>
 133
 134         <refsect1>
 135                   <title>See Also</title>
 136                   <para>
 137                           <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 138                           <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 139                           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 140                           <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 141                           <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 142                           <citerefentry><refentrytitle>swapon</refentrytitle><manvolnum>8</manvolnum></citerefentry>
 143                   </para>
 144         </refsect1>
 145
 146 </refentry>