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. 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>
 104
 105                 <variablelist>
 106
 107                         <varlistentry>
 108                                 <term><varname>What=</varname></term>
 109                                 <listitem><para>Takes an absolute path
 110                                 of a device node or file to use for
 111                                 paging. See
 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
 121                                 created. (See
 122                                 <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 123                                 for more information.) This option is
 124                                 mandatory.</para></listitem>
 125                         </varlistentry>
 126
 127                         <varlistentry>
 128                                 <term><varname>Priority=</varname></term>
 129
 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>
 134                         </varlistentry>
 135
 136                         <varlistentry>
 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
 151                                 logic. Defaults to
 152                                 60s.</para></listitem>
 153                         </varlistentry>
 154
 155                         <varlistentry>
 156                                 <term><varname>KillMode=</varname></term>
 157                                 <listitem><para>Specifies how
 158                                 processes of this swap shall be
 159                                 killed. One of
 160                                 <option>control-group</option>,
 161                                 <option>process-group</option>,
 162                                 <option>process</option>,
 163                                 <option>none</option>.</para>
 164
 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>
 170                         </varlistentry>
 171
 172                         <varlistentry>
 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.
 177                                 </para></listitem>
 178                         </varlistentry>
 179
 180                         <varlistentry>
 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".
 188                                 </para></listitem>
 189                         </varlistentry>
 190                 </variablelist>
 191         </refsect1>
 192
 193         <refsect1>
 194                   <title>See Also</title>
 195                   <para>
 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>
 203                   </para>
 204         </refsect1>
 205
 206 </refentry>