[thirdparty/systemd.git] / man / systemd.kill.xml

<?xml version='1.0'?> <!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
  "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->

<refentry id="systemd.kill" xmlns:xi="http://www.w3.org/2001/XInclude">
  <refentryinfo>
    <title>systemd.kill</title>
    <productname>systemd</productname>
  </refentryinfo>

  <refmeta>
    <refentrytitle>systemd.kill</refentrytitle>
    <manvolnum>5</manvolnum>
  </refmeta>

  <refnamediv>
    <refname>systemd.kill</refname>
    <refpurpose>Process killing procedure
    configuration</refpurpose>
  </refnamediv>

  <refsynopsisdiv>
    <para><filename><replaceable>service</replaceable>.service</filename>,
    <filename><replaceable>socket</replaceable>.socket</filename>,
    <filename><replaceable>mount</replaceable>.mount</filename>,
    <filename><replaceable>swap</replaceable>.swap</filename>,
    <filename><replaceable>scope</replaceable>.scope</filename></para>
  </refsynopsisdiv>

  <refsect1>
    <title>Description</title>

    <para>Unit configuration files for services, sockets, mount
    points, swap devices and scopes share a subset of configuration
    options which define the killing procedure of processes belonging
    to the unit.</para>

    <para>This man page lists the configuration options shared by
    these five unit types. See
    <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
    for the common options shared by all unit configuration files, and
    <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
    <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
    <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
    <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
    and
    <citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry>
    for more information on the configuration file options specific to
    each unit type.</para>

    <para>The kill procedure configuration options are configured in
    the [Service], [Socket], [Mount] or [Swap] section, depending on
    the unit type.</para>
  </refsect1>

  <refsect1>
    <title>Options</title>

    <variablelist class='unit-directives'>

      <varlistentry>
        <term><varname>KillMode=</varname></term>
        <listitem><para>Specifies how processes of this unit shall be killed. One of
        <option>control-group</option>, <option>mixed</option>, <option>process</option>,
        <option>none</option>.</para>

        <para>If set to <option>control-group</option>, all remaining processes in the control group of this
        unit will be killed on unit stop (for services: after the stop command is executed, as configured
        with <varname>ExecStop=</varname>). If set to <option>mixed</option>, the
        <constant>SIGTERM</constant> signal (see below) is sent to the main process while the subsequent
        <constant>SIGKILL</constant> signal (see below) is sent to all remaining processes of the unit's
        control group. If set to <option>process</option>, only the main process itself is killed (not
        recommended!). If set to <option>none</option>, no process is killed (strongly recommended
        against!). In this case, only the stop command will be executed on unit stop, but no process will be
        killed otherwise.  Processes remaining alive after stop are left in their control group and the
        control group continues to exist after stop unless empty.</para>

        <para>Note that it is not recommended to set <varname>KillMode=</varname> to
        <constant>process</constant> or even <constant>none</constant>, as this allows processes to escape
        the service manager's lifecycle and resource management, and to remain running even while their
        service is considered stopped and is assumed to not consume any resources.</para>

        <para>Processes will first be terminated via <constant>SIGTERM</constant> (unless the signal to send
        is changed via <varname>KillSignal=</varname> or <varname>RestartKillSignal=</varname>). Optionally,
        this is immediately followed by a <constant>SIGHUP</constant> (if enabled with
        <varname>SendSIGHUP=</varname>). If processes still remain after:
        <itemizedlist>
          <listitem><para>the main process of a unit has exited (applies to <varname>KillMode=</varname>:
              <option>mixed</option>)</para></listitem>
          <listitem><para>the delay configured via the <varname>TimeoutStopSec=</varname> has passed
              (applies to <varname>KillMode=</varname>: <option>control-group</option>, <option>mixed</option>,
              <option>process</option>)</para></listitem>
        </itemizedlist>

        the termination request is repeated with the <constant>SIGKILL</constant> signal or the signal specified via
        <varname>FinalKillSignal=</varname> (unless this is disabled via the <varname>SendSIGKILL=</varname>
        option). See <citerefentry><refentrytitle>kill</refentrytitle><manvolnum>2</manvolnum></citerefentry>
        for more information.</para>

        <para>Defaults to <option>control-group</option>.</para>

        <xi:include href="version-info.xml" xpointer="v187"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>KillSignal=</varname></term>
        <listitem><para>Specifies which signal to use when stopping a service. This controls the signal that
        is sent as first step of shutting down a unit (see above), and is usually followed by
        <constant>SIGKILL</constant> (see above and below). For a list of valid signals, see
        <citerefentry project='man-pages'><refentrytitle>signal</refentrytitle><manvolnum>7</manvolnum></citerefentry>.
        Defaults to <constant>SIGTERM</constant>.</para>

        <para>Note that, right after sending the signal specified in this setting, systemd will always send
        <constant>SIGCONT</constant>, to ensure that even suspended tasks can be terminated cleanly.</para>

        <xi:include href="version-info.xml" xpointer="v187"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>RestartKillSignal=</varname></term>
        <listitem><para>Specifies which signal to use when restarting a service. The same as
        <varname>KillSignal=</varname> described above, with the exception that this setting is used in a
        restart job. Not set by default, and the value of <varname>KillSignal=</varname> is used.</para>

        <xi:include href="version-info.xml" xpointer="v244"/>
        </listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>SendSIGHUP=</varname></term>
        <listitem><para>Specifies whether to send
        <constant>SIGHUP</constant> to remaining processes immediately
        after sending the signal configured with
        <varname>KillSignal=</varname>. This is useful to indicate to
        shells and shell-like programs that their connection has been
        severed. Takes a boolean value. Defaults to <literal>no</literal>.
        </para>

        <xi:include href="version-info.xml" xpointer="v207"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>SendSIGKILL=</varname></term>
        <listitem><para>Specifies whether to send
        <constant>SIGKILL</constant> (or the signal specified by
        <varname>FinalKillSignal=</varname>) to remaining processes
        after a timeout, if the normal shutdown procedure left
        processes of the service around. When disabled, a
        <varname>KillMode=</varname> of <constant>control-group</constant>
        or <constant>mixed</constant> service will not restart if
        processes from prior services exist within the control group.
        Takes a boolean value. Defaults to <literal>yes</literal>.
        </para>

        <xi:include href="version-info.xml" xpointer="v187"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>FinalKillSignal=</varname></term>
        <listitem><para>Specifies which signal to send to remaining
        processes after a timeout if <varname>SendSIGKILL=</varname>
        is enabled. The signal configured here should be one that is
        not typically caught and processed by services (<constant>SIGTERM</constant>
        is not suitable). Developers can find it useful to use this to
        generate a coredump to troubleshoot why a service did not
        terminate upon receiving the initial <constant>SIGTERM</constant>
        signal. This can be achieved by configuring <varname>LimitCORE=</varname>
        and setting <varname>FinalKillSignal=</varname> to either
        <constant>SIGQUIT</constant> or <constant>SIGABRT</constant>.
        Defaults to <constant>SIGKILL</constant>.
        </para>

        <xi:include href="version-info.xml" xpointer="v240"/></listitem>
      </varlistentry>

      <varlistentry>
        <term><varname>WatchdogSignal=</varname></term>
        <listitem><para>Specifies which signal to use to terminate the
        service when the watchdog timeout expires (enabled through
        <varname>WatchdogSec=</varname>). Defaults to <constant>SIGABRT</constant>.
        </para>

        <xi:include href="version-info.xml" xpointer="v240"/></listitem>
      </varlistentry>

    </variablelist>
  </refsect1>

  <refsect1>
      <title>See Also</title>
      <para><simplelist type="inline">
        <member><citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
        <member><citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
        <member><citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
        <member><citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
        <member><citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
        <member><citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
        <member><citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
        <member><citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
        <member><citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
        <member><citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry></member>
        <member><citerefentry><refentrytitle>kill</refentrytitle><manvolnum>2</manvolnum></citerefentry></member>
        <member><citerefentry project='man-pages'><refentrytitle>signal</refentrytitle><manvolnum>7</manvolnum></citerefentry></member>
      </simplelist></para>
  </refsect1>

</refentry>
Commit	Line	Data
4819ff03	1	<?xml version='1.0'?> <!---nxml--->
3a54a157	2	<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
eea10b26	3	"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
db9ecf05	4	<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
4819ff03	5
4623eecb	6	<refentry id="systemd.kill" xmlns:xi="http://www.w3.org/2001/XInclude">
798d3a52 ZJS	7	<refentryinfo>
	8	<title>systemd.kill</title>
	9	<productname>systemd</productname>
798d3a52 ZJS	10	</refentryinfo>
	11
	12	<refmeta>
	13	<refentrytitle>systemd.kill</refentrytitle>
	14	<manvolnum>5</manvolnum>
	15	</refmeta>
	16
	17	<refnamediv>
	18	<refname>systemd.kill</refname>
	19	<refpurpose>Process killing procedure
	20	configuration</refpurpose>
	21	</refnamediv>
	22
	23	<refsynopsisdiv>
	24	<para><filename><replaceable>service</replaceable>.service</filename>,
	25	<filename><replaceable>socket</replaceable>.socket</filename>,
	26	<filename><replaceable>mount</replaceable>.mount</filename>,
	27	<filename><replaceable>swap</replaceable>.swap</filename>,
	28	<filename><replaceable>scope</replaceable>.scope</filename></para>
	29	</refsynopsisdiv>
	30
	31	<refsect1>
	32	<title>Description</title>
	33
	34	<para>Unit configuration files for services, sockets, mount
	35	points, swap devices and scopes share a subset of configuration
	36	options which define the killing procedure of processes belonging
	37	to the unit.</para>
	38
	39	<para>This man page lists the configuration options shared by
	40	these five unit types. See
	41	<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
	42	for the common options shared by all unit configuration files, and
	43	<citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
	44	<citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
	45	<citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
	46	<citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>
	47	and
	48	<citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry>
	49	for more information on the configuration file options specific to
	50	each unit type.</para>
	51
	52	<para>The kill procedure configuration options are configured in
	53	the [Service], [Socket], [Mount] or [Swap] section, depending on
	54	the unit type.</para>
	55	</refsect1>
	56
	57	<refsect1>
	58	<title>Options</title>
	59
	60	<variablelist class='unit-directives'>
	61
	62	<varlistentry>
	63	<term><varname>KillMode=</varname></term>
9b52e0d8 LP	64	<listitem><para>Specifies how processes of this unit shall be killed. One of
9b52e0d8 LP	65	<option>control-group</option>, <option>mixed</option>, <option>process</option>,
798d3a52 ZJS	66	<option>none</option>.</para>
798d3a52 ZJS	67
9b52e0d8 LP	68	<para>If set to <option>control-group</option>, all remaining processes in the control group of this
	69	unit will be killed on unit stop (for services: after the stop command is executed, as configured
	70	with <varname>ExecStop=</varname>). If set to <option>mixed</option>, the
	71	<constant>SIGTERM</constant> signal (see below) is sent to the main process while the subsequent
	72	<constant>SIGKILL</constant> signal (see below) is sent to all remaining processes of the unit's
	73	control group. If set to <option>process</option>, only the main process itself is killed (not
	74	recommended!). If set to <option>none</option>, no process is killed (strongly recommended
	75	against!). In this case, only the stop command will be executed on unit stop, but no process will be
	76	killed otherwise. Processes remaining alive after stop are left in their control group and the
	77	control group continues to exist after stop unless empty.</para>
	78
	79	<para>Note that it is not recommended to set <varname>KillMode=</varname> to
	80	<constant>process</constant> or even <constant>none</constant>, as this allows processes to escape
	81	the service manager's lifecycle and resource management, and to remain running even while their
	82	service is considered stopped and is assumed to not consume any resources.</para>
798d3a52	83
2e34d21b	84	<para>Processes will first be terminated via <constant>SIGTERM</constant> (unless the signal to send
b557f1c1 ZJS	85	is changed via <varname>KillSignal=</varname> or <varname>RestartKillSignal=</varname>). Optionally,
b557f1c1 ZJS	86	this is immediately followed by a <constant>SIGHUP</constant> (if enabled with
f63e259b CBI	87	<varname>SendSIGHUP=</varname>). If processes still remain after:
	88	<itemizedlist>
	89	<listitem><para>the main process of a unit has exited (applies to <varname>KillMode=</varname>:
	90	<option>mixed</option>)</para></listitem>
	91	<listitem><para>the delay configured via the <varname>TimeoutStopSec=</varname> has passed
	92	(applies to <varname>KillMode=</varname>: <option>control-group</option>, <option>mixed</option>,
	93	<option>process</option>)</para></listitem>
	94	</itemizedlist>
	95
	96	the termination request is repeated with the <constant>SIGKILL</constant> signal or the signal specified via
b557f1c1 ZJS	97	<varname>FinalKillSignal=</varname> (unless this is disabled via the <varname>SendSIGKILL=</varname>
	98	option). See <citerefentry><refentrytitle>kill</refentrytitle><manvolnum>2</manvolnum></citerefentry>
	99	for more information.</para>
2e34d21b	100
ec07c3c8 AK	101	<para>Defaults to <option>control-group</option>.</para>
	102
	103	<xi:include href="version-info.xml" xpointer="v187"/></listitem>
798d3a52 ZJS	104	</varlistentry>
	105
	106	<varlistentry>
	107	<term><varname>KillSignal=</varname></term>
b557f1c1 ZJS	108	<listitem><para>Specifies which signal to use when stopping a service. This controls the signal that
	109	is sent as first step of shutting down a unit (see above), and is usually followed by
	110	<constant>SIGKILL</constant> (see above and below). For a list of valid signals, see
3ba3a79d	111	<citerefentry project='man-pages'><refentrytitle>signal</refentrytitle><manvolnum>7</manvolnum></citerefentry>.
b557f1c1	112	Defaults to <constant>SIGTERM</constant>.</para>
e8c53936	113
b557f1c1 ZJS	114	<para>Note that, right after sending the signal specified in this setting, systemd will always send
b557f1c1 ZJS	115	<constant>SIGCONT</constant>, to ensure that even suspended tasks can be terminated cleanly.</para>
ec07c3c8 AK	116
ec07c3c8 AK	117	<xi:include href="version-info.xml" xpointer="v187"/>
b557f1c1 ZJS	118	</listitem>
	119	</varlistentry>
	120
	121	<varlistentry>
	122	<term><varname>RestartKillSignal=</varname></term>
	123	<listitem><para>Specifies which signal to use when restarting a service. The same as
	124	<varname>KillSignal=</varname> described above, with the exception that this setting is used in a
	125	restart job. Not set by default, and the value of <varname>KillSignal=</varname> is used.</para>
ec07c3c8 AK	126
ec07c3c8 AK	127	<xi:include href="version-info.xml" xpointer="v244"/>
e8c53936	128	</listitem>
798d3a52 ZJS	129	</varlistentry>
	130
	131	<varlistentry>
	132	<term><varname>SendSIGHUP=</varname></term>
	133	<listitem><para>Specifies whether to send
	134	<constant>SIGHUP</constant> to remaining processes immediately
	135	after sending the signal configured with
	136	<varname>KillSignal=</varname>. This is useful to indicate to
	137	shells and shell-like programs that their connection has been
477eac0a	138	severed. Takes a boolean value. Defaults to <literal>no</literal>.
ec07c3c8 AK	139	</para>
	140
	141	<xi:include href="version-info.xml" xpointer="v207"/></listitem>
798d3a52 ZJS	142	</varlistentry>
	143
	144	<varlistentry>
	145	<term><varname>SendSIGKILL=</varname></term>
	146	<listitem><para>Specifies whether to send
fbb48d4c JR	147	<constant>SIGKILL</constant> (or the signal specified by
	148	<varname>FinalKillSignal=</varname>) to remaining processes
	149	after a timeout, if the normal shutdown procedure left
c53d2d54 DB	150	processes of the service around. When disabled, a
	151	<varname>KillMode=</varname> of <constant>control-group</constant>
	152	or <constant>mixed</constant> service will not restart if
	153	processes from prior services exist within the control group.
477eac0a	154	Takes a boolean value. Defaults to <literal>yes</literal>.
ec07c3c8 AK	155	</para>
	156
	157	<xi:include href="version-info.xml" xpointer="v187"/></listitem>
fbb48d4c JR	158	</varlistentry>
	159
	160	<varlistentry>
	161	<term><varname>FinalKillSignal=</varname></term>
	162	<listitem><para>Specifies which signal to send to remaining
	163	processes after a timeout if <varname>SendSIGKILL=</varname>
	164	is enabled. The signal configured here should be one that is
	165	not typically caught and processed by services (<constant>SIGTERM</constant>
	166	is not suitable). Developers can find it useful to use this to
	167	generate a coredump to troubleshoot why a service did not
	168	terminate upon receiving the initial <constant>SIGTERM</constant>
	169	signal. This can be achieved by configuring <varname>LimitCORE=</varname>
	170	and setting <varname>FinalKillSignal=</varname> to either
e9dd6984	171	<constant>SIGQUIT</constant> or <constant>SIGABRT</constant>.
fbb48d4c	172	Defaults to <constant>SIGKILL</constant>.
ec07c3c8 AK	173	</para>
	174
	175	<xi:include href="version-info.xml" xpointer="v240"/></listitem>
798d3a52 ZJS	176	</varlistentry>
798d3a52 ZJS	177
c87700a1 AZ	178	<varlistentry>
	179	<term><varname>WatchdogSignal=</varname></term>
	180	<listitem><para>Specifies which signal to use to terminate the
	181	service when the watchdog timeout expires (enabled through
	182	<varname>WatchdogSec=</varname>). Defaults to <constant>SIGABRT</constant>.
ec07c3c8 AK	183	</para>
	184
	185	<xi:include href="version-info.xml" xpointer="v240"/></listitem>
c87700a1 AZ	186	</varlistentry>
c87700a1 AZ	187
798d3a52 ZJS	188	</variablelist>
	189	</refsect1>
	190
	191	<refsect1>
	192	<title>See Also</title>
13a69c12 DT	193	<para><simplelist type="inline">
	194	<member><citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
	195	<member><citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
	196	<member><citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
	197	<member><citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
	198	<member><citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
	199	<member><citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
	200	<member><citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
	201	<member><citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
	202	<member><citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry></member>
	203	<member><citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry></member>
	204	<member><citerefentry><refentrytitle>kill</refentrytitle><manvolnum>2</manvolnum></citerefentry></member>
	205	<member><citerefentry project='man-pages'><refentrytitle>signal</refentrytitle><manvolnum>7</manvolnum></citerefentry></member>
	206	</simplelist></para>
798d3a52	207	</refsect1>
4819ff03 LP	208
4819ff03 LP	209	</refentry>