<title>Description</title>
<para>A unit configuration file whose name ends in
- <filename>.swap</filename> encodes information about a
+ <literal>.swap</literal> encodes information about a
swap device or file for memory paging controlled and
supervised by systemd.</para>
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>
+ <citerefentry><refentrytitle>systemd.kill</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
which define the way the processes are
- terminated.</para>
+ 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>/dev/sda5</filename> must be configured in a
+ <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
+ 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
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
+ <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>
+ <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. Option <option>auto</option> has the
+ opposite meaning and is the default.</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>nofail</option></term>
+ <term><option>fail</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. Option
+ <option>fail</option> has the opposite meaning and
+ is the default.</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
</refsect1>
<refsect1>
setting is optional.</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><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
+ within the configured time, the swap
will be considered failed and be shut
down again. All commands still running
will be terminated forcibly via
- SIGTERM, and after another delay of
- this time with SIGKILL. (See
+ <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 0 to disable the timeout
- logic. Defaults to
- 90s.</para></listitem>
+ 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>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</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>,