240 lines
11 KiB
XML
240 lines
11 KiB
XML
<?xml version='1.0'?> <!--*-nxml-*-->
|
|
<!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 project='man-pages'><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 project='man-pages'><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>When reading <filename>/etc/fstab</filename>, a few special
|
|
options are understood by systemd which influence how dependencies
|
|
are created for swap units.</para>
|
|
|
|
<variablelist class='fstab-options'>
|
|
<varlistentry>
|
|
<term><option>noauto</option></term>
|
|
<term><option>auto</option></term>
|
|
|
|
<listitem><para>With <option>noauto</option>, the swap unit
|
|
will not be added as a dependency for
|
|
<filename>swap.target</filename>. This means that it will not
|
|
be activated automatically during boot, unless it is pulled in
|
|
by some other unit. The <option>auto</option> option has the
|
|
opposite meaning and is the default.</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><option>nofail</option></term>
|
|
|
|
<listitem><para>With <option>nofail</option>, the swap unit
|
|
will be only wanted, not required by
|
|
<filename>swap.target</filename>. This means that the boot
|
|
will continue even if this swap device is not activated
|
|
successfully.</para>
|
|
</listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</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 project='man-pages'><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 and ignored when the priority is set by <option>pri=</option> in the
|
|
<varname>Options=</varname> key.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><varname>Options=</varname></term>
|
|
|
|
<listitem><para>May contain an option string for the swap
|
|
device. This may be used for controlling discard options among
|
|
other functionality, if the swap backing device supports the
|
|
discard or trim operation. (See
|
|
<citerefentry project='man-pages'><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-system.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 project='man-pages'><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>
|