mirror of
https://github.com/systemd/systemd.git
synced 2024-11-01 17:51:22 +03:00
235 lines
13 KiB
XML
235 lines
13 KiB
XML
<?xml version='1.0'?> <!--*-nxml-*-->
|
|
<?xml-stylesheet type="text/xsl" href="http://docbook.sourceforge.net/release/xsl/current/xhtml/docbook.xsl"?>
|
|
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
|
|
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
|
|
|
|
<!--
|
|
This file is part of systemd.
|
|
|
|
Copyright 2010 Lennart Poettering
|
|
|
|
systemd is free software; you can redistribute it and/or modify it
|
|
under the terms of the GNU Lesser General Public License as published by
|
|
the Free Software Foundation; either version 2.1 of the License, or
|
|
(at your option) any later version.
|
|
|
|
systemd is distributed in the hope that it will be useful, but
|
|
WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public License
|
|
along with systemd; If not, see <http://www.gnu.org/licenses/>.
|
|
-->
|
|
|
|
<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>Swap unit configuration</refpurpose>
|
|
</refnamediv>
|
|
|
|
<refsynopsisdiv>
|
|
<para><filename><replaceable>swap</replaceable>.swap</filename></para>
|
|
</refsynopsisdiv>
|
|
|
|
<refsect1>
|
|
<title>Description</title>
|
|
|
|
<para>A unit configuration file whose name ends in
|
|
<literal>.swap</literal> 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>Additional options are listed in
|
|
<citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
|
which define the execution environment the
|
|
<citerefentry><refentrytitle>swapon</refentrytitle><manvolnum>8</manvolnum></citerefentry>
|
|
binary is executed in, and in
|
|
<citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
|
which define the way the processes are
|
|
terminated, and in
|
|
<citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
|
which configure resource control settings for the
|
|
processes of the service.</para>
|
|
|
|
<para>Swap units must be named after the devices
|
|
or files they control. Example: the swap device
|
|
<filename noindex='true'>/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>
|
|
|
|
<para>All swap units automatically get the appropriate
|
|
dependencies on the devices or on the mount points
|
|
of the files they are activated from.</para>
|
|
|
|
<para>Swap units with
|
|
<varname>DefaultDependencies=</varname> enabled
|
|
implicitly acquire a conflicting dependency to
|
|
<filename>umount.target</filename> so that they are
|
|
deactivated at shutdown.</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). Swaps listed in
|
|
<filename>/etc/fstab</filename> will be converted into
|
|
native units dynamically at boot and when the
|
|
configuration of the system manager is
|
|
reloaded. See
|
|
<citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>
|
|
for details about the conversion.</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>
|
|
|
|
<para>Unless the <option>noauto</option> option is set
|
|
for them all swap units configured in
|
|
<filename>/etc/fstab</filename> are also added as
|
|
requirements to <filename>swap.target</filename>, so
|
|
that they are waited for and activated during
|
|
boot.</para>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>Options</title>
|
|
|
|
<para>Swap files must include a [Swap] section, which
|
|
carries information about the swap device it
|
|
supervises. A number of options that may be used in
|
|
this section are shared with other unit types. These
|
|
options are documented in
|
|
<citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
|
|
and
|
|
<citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>. The
|
|
options specific to the [Swap] section of swap units
|
|
are the following:</para>
|
|
|
|
<variablelist class='unit-directives'>
|
|
|
|
<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>
|
|
|
|
<varlistentry>
|
|
<term><varname>Discard=</varname></term>
|
|
|
|
<listitem><para>Enable discards, if the swap
|
|
backing device supports the discard or trim
|
|
operation. Can be one of <literal>none</literal>,
|
|
<literal>once</literal>, <literal>pages</literal>
|
|
or <literal>all</literal>. Defaults to
|
|
<literal>none</literal>. (See
|
|
<citerefentry><refentrytitle>swapon</refentrytitle><manvolnum>8</manvolnum></citerefentry>
|
|
for more information.)
|
|
</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><varname>TimeoutSec=</varname></term>
|
|
<listitem><para>Configures the time to
|
|
wait for the swapon command to
|
|
finish. If a command does not exit
|
|
within the configured time, the swap
|
|
will be considered failed and be shut
|
|
down again. All commands still running
|
|
will be terminated forcibly via
|
|
<constant>SIGTERM</constant>, and after another delay of
|
|
this time with <constant>SIGKILL</constant>. (See
|
|
<option>KillMode=</option> in
|
|
<citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>.)
|
|
Takes a unit-less value in seconds, or
|
|
a time span value such as "5min
|
|
20s". Pass <literal>0</literal> to disable the timeout
|
|
logic. Defaults to <varname>DefaultTimeoutStartSec=</varname> from the
|
|
manager configuration file
|
|
(see <citerefentry><refentrytitle>systemd-systemd.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>).
|
|
</para></listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
|
|
<para>Check
|
|
<citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
|
|
and
|
|
<citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>
|
|
for more settings.</para>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>See Also</title>
|
|
<para>
|
|
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>systemd.resource-control</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>,
|
|
<citerefentry><refentrytitle>systemd-fstab-generator</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>
|
|
</para>
|
|
</refsect1>
|
|
|
|
</refentry>
|