<refsect1>
<title>Description</title>
- <para>systemd is a system and service manager for Linux operating
- systems. When run as first process on boot (as PID 1), it acts as
- init system that brings up and maintains userspace
- services.</para>
-
- <para>For compatibility with SysV, if systemd is called as
- <command>init</command> and a PID that is not 1, it will execute
- <command>telinit</command> and pass all command line arguments
- unmodified. That means <command>init</command> and
- <command>telinit</command> are mostly equivalent when invoked from
- normal login sessions. See
- <citerefentry><refentrytitle>telinit</refentrytitle><manvolnum>8</manvolnum></citerefentry>
- for more information.</para>
+ <para>systemd is a system and service manager for Linux operating systems. When run as first process on
+ boot (as PID 1), it acts as init system that brings up and maintains userspace services. Seperate
+ instances are started for logged-in users to start their services.</para>
+
+ <para><command>systemd</command> is usually not invoked directly by the user, but is installed as the
+ <filename>/sbin/init</filename> symlink and started during early boot. The user manager instances are
+ started automatically through the
+ <citerefentry><refentrytitle>user@.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ service.</para>
+
+ <para>For compatibility with SysV, if the binary is called as <command>init</command> and is not the
+ first process on the machine (PID is not 1), it will execute <command>telinit</command> and pass all
+ command line arguments unmodified. That means <command>init</command> and <command>telinit</command> are
+ mostly equivalent when invoked from normal login sessions. See
+ <citerefentry><refentrytitle>telinit</refentrytitle><manvolnum>8</manvolnum></citerefentry> for more
+ information.</para>
<para>When run as a system instance, systemd interprets the
configuration file <filename>system.conf</filename> and the files
for more information.</para>
</refsect1>
- <refsect1>
- <title>Options</title>
-
- <para>The following options are understood:</para>
-
- <variablelist>
- <varlistentry>
- <term><option>--test</option></term>
-
- <listitem><para>Determine the initial start-up transaction (i.e. the list of jobs enqueued at
- start-up), dump it and exit — without actually executing any of the determined jobs. This option is
- useful for debugging only. Note that during regular service manager start-up additional units not
- shown by this operation may be started, because hardware, socket, bus or other kinds of activation
- might add additional jobs as the transaction is executed. Use <option>--system</option> to request
- the initial transaction of the system service manager (this is also the implied default), combine
- with <option>--user</option> to request the initial transaction of the per-user service manager
- instead.</para></listitem>
- </varlistentry>
- <varlistentry>
- <term><option>--dump-configuration-items</option></term>
-
- <listitem><para>Dump understood unit configuration items. This
- outputs a terse but complete list of configuration items
- understood in unit definition files.</para></listitem>
- </varlistentry>
- <varlistentry>
- <term><option>--dump-bus-properties</option></term>
-
- <listitem><para>Dump exposed bus properties. This outputs a terse but complete list of properties
- exposed on D-Bus.</para></listitem>
- </varlistentry>
- <varlistentry>
- <term><option>--unit=</option></term>
-
- <listitem><para>Set default unit to activate on startup. If
- not specified, defaults to
- <filename>default.target</filename>.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><option>--system</option></term>
- <term><option>--user</option></term>
-
- <listitem><para>When used in conjunction with <option>--test</option>, selects whether to calculate
- the initial transaction for the system instance or for a per-user instance. These options have no
- effect when invoked without <option>--test</option>, as during regular
- (i.e. non-<option>--test</option>) invocations the service manager will automatically detect whether
- it shall operate in system or per-user mode, by checking whether the PID it is run as is 1 or
- not. Note that it is not supported booting and maintaining a system with the service manager running
- in <option>--system</option> mode but with a PID other than 1.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><option>--dump-core</option></term>
-
- <listitem><para>Enable core dumping on crash. This switch has
- no effect when running as user instance. This setting may also
- be enabled during boot on the kernel command line via the
- <varname>systemd.dump_core=</varname> option, see
- below.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><option>--crash-vt=</option><replaceable>VT</replaceable></term>
-
- <listitem><para>Switch to a specific virtual console (VT) on
- crash. Takes a positive integer in the range 1–63, or a
- boolean argument. If an integer is passed, selects which VT to
- switch to. If <constant>yes</constant>, the VT kernel messages
- are written to is selected. If <constant>no</constant>, no VT
- switch is attempted. This switch has no effect when running as
- user instance. This setting may also be enabled during boot,
- on the kernel command line via the
- <varname>systemd.crash_vt=</varname> option, see
- <!-- FIXME: there is no crash_vt command line option? -->
- below.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><option>--crash-shell</option></term>
-
- <listitem><para>Run a shell on crash. This switch has no
- effect when running as user instance. This setting may also be
- enabled during boot, on the kernel command line via the
- <varname>systemd.crash_shell=</varname> option, see
- below.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><option>--crash-reboot</option></term>
-
- <listitem><para>Automatically reboot the system on crash. This
- switch has no effect when running as user instance. This
- setting may also be enabled during boot, on the kernel command
- line via the <varname>systemd.crash_reboot=</varname> option,
- see below.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><option>--confirm-spawn</option></term>
-
- <listitem><para>Ask for confirmation when spawning processes.
- This switch has no effect when run as user
- instance.</para></listitem>
- </varlistentry>
- <varlistentry>
- <term><option>--show-status=</option></term>
-
- <listitem><para>Takes a boolean argument or the special value <constant>auto</constant>. If on, terse unit
- status information is shown on the console during boot-up and shutdown. If off, no such status information is
- shown. If set to <constant>auto</constant> behavior is similar to off, except that it is automatically switched
- to on, as soon as the first unit failure or significant boot delay is encountered. This switch has no effect
- when invoked as user instance. If specified, overrides both the kernel command line setting
- <varname>systemd.show_status=</varname> (see below) and the configuration file option
- <option>ShowStatus=</option>, see
- <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem>
- </varlistentry>
- <varlistentry>
- <term><option>--log-target=</option></term>
-
- <listitem><para>Set log target. Argument must be one of
- <option>console</option>,
- <option>journal</option>,
- <option>kmsg</option>,
- <option>journal-or-kmsg</option>,
- <option>null</option>.</para></listitem>
- </varlistentry>
- <varlistentry>
- <term><option>--log-level=</option></term>
-
- <listitem><para>Set log level. As
- argument this accepts a numerical log
- level or the well-known <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
- symbolic names (lowercase):
- <option>emerg</option>,
- <option>alert</option>,
- <option>crit</option>,
- <option>err</option>,
- <option>warning</option>,
- <option>notice</option>,
- <option>info</option>,
- <option>debug</option>.</para></listitem>
- </varlistentry>
- <varlistentry>
- <term><option>--log-color=</option></term>
-
- <listitem><para>Highlight important log messages. Argument is
- a boolean value. If the argument is omitted, it defaults to
- <option>true</option>.</para></listitem>
- </varlistentry>
- <varlistentry>
- <term><option>--log-location=</option></term>
-
- <listitem><para>Include code location in log messages. This is
- mostly relevant for debugging purposes. Argument is a boolean
- value. If the argument is omitted it defaults to
- <option>true</option>.</para></listitem>
- </varlistentry>
- <varlistentry>
- <term><option>--default-standard-output=</option></term>
- <term><option>--default-standard-error=</option></term>
-
- <listitem><para>Sets the default output or error output for
- all services and sockets, respectively. That is, controls the
- default for <option>StandardOutput=</option> and
- <option>StandardError=</option> (see
- <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
- for details). Takes one of
- <option>inherit</option>,
- <option>null</option>,
- <option>tty</option>,
- <option>journal</option>,
- <option>journal+console</option>,
- <option>kmsg</option>,
- <option>kmsg+console</option>. If the
- argument is omitted
- <option>--default-standard-output=</option> defaults to
- <option>journal</option> and
- <option>--default-standard-error=</option> to
- <option>inherit</option>.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><option>--machine-id=</option></term>
-
- <listitem><para>Override the machine-id set on the hard drive,
- useful for network booting or for containers. May not be set
- to all zeros.</para></listitem>
- </varlistentry>
-
- <varlistentry>
- <term><option>--service-watchdogs=</option></term>
-
- <listitem><para>Globally enable/disable all service watchdog timeouts and emergency
- actions. This setting may also be specified during boot, on the kernel
- command line via the <varname>systemd.service_watchdogs=</varname>
- option, see below. Defaults to enabled.</para></listitem>
- </varlistentry>
-
- <xi:include href="standard-options.xml" xpointer="help" />
- <xi:include href="standard-options.xml" xpointer="version" />
- </variablelist>
- </refsect1>
-
<refsect1>
<title>Concepts</title>
it defaults to <constant>auto</constant>. If specified overrides the system
manager configuration file option <option>ShowStatus=</option>, see
<citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
- However, the process command line option <option>--show-status=</option>
- takes precedence over both this kernel command line option and the
- configuration file option.</para></listitem>
+ </para></listitem>
</varlistentry>
<varlistentry>
<varlistentry>
<term><varname>systemd.default_standard_output=</varname></term>
<term><varname>systemd.default_standard_error=</varname></term>
- <listitem><para>Controls default standard output and error
- output for services, with the same effect as the
- <option>--default-standard-output=</option> and
- <option>--default-standard-error=</option> command line
- arguments described above, respectively.</para></listitem>
+
+ <listitem><para>Controls default standard output and error output for services and sockets. That is,
+ controls the default for <option>StandardOutput=</option> and <option>StandardError=</option> (see
+ <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry> for
+ details). Takes one of <option>inherit</option>, <option>null</option>, <option>tty</option>,
+ <option>journal</option>, <option>journal+console</option>, <option>kmsg</option>,
+ <option>kmsg+console</option>. If the argument is omitted
+ <varname>systemd.default-standard-output=</varname> defaults to <option>journal</option> and
+ <varname>systemd.default-standard-error=</varname> to <option>inherit</option>.</para></listitem>
</varlistentry>
<varlistentry>
<citerefentry><refentrytitle>kernel-command-line</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para>
</refsect1>
+ <refsect1>
+ <title>Options</title>
+
+ <para><command>systemd</command> is only very rarely invoked directly, since it is started early and is
+ already running by the time users may interact with it. Normally, tools like
+ <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> are used to
+ give commands to the manager. Since <command>systemd</command> is usually not invoked directly, the
+ options listed below are mostly useful for debugging and special purposes.</para>
+
+ <refsect2>
+ <title>Introspection and debugging options</title>
+
+ <para>Those options are used for testing and introspection, and <command>systemd</command> may
+ be invoked with them at any time:</para>
+
+ <variablelist>
+ <varlistentry>
+ <term><option>--dump-configuration-items</option></term>
+
+ <listitem><para>Dump understood unit configuration items. This outputs a terse but complete list of
+ configuration items understood in unit definition files.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--dump-bus-properties</option></term>
+
+ <listitem><para>Dump exposed bus properties. This outputs a terse but complete list of properties
+ exposed on D-Bus.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--test</option></term>
+
+ <listitem><para>Determine the initial start-up transaction (i.e. the list of jobs enqueued at
+ start-up), dump it and exit — without actually executing any of the determined jobs. This option is
+ useful for debugging only. Note that during regular service manager start-up additional units not
+ shown by this operation may be started, because hardware, socket, bus or other kinds of activation
+ might add additional jobs as the transaction is executed. Use <option>--system</option> to request
+ the initial transaction of the system service manager (this is also the implied default), combine
+ with <option>--user</option> to request the initial transaction of the per-user service manager
+ instead.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--system</option></term>
+ <term><option>--user</option></term>
+
+ <listitem><para>When used in conjunction with <option>--test</option>, selects whether to calculate
+ the initial transaction for the system instance or for a per-user instance. These options have no
+ effect when invoked without <option>--test</option>, as during regular
+ (i.e. non-<option>--test</option>) invocations the service manager will automatically detect
+ whether it shall operate in system or per-user mode, by checking whether the PID it is run as is 1
+ or not. Note that it is not supported booting and maintaining a system with the service manager
+ running in <option>--system</option> mode but with a PID other than 1.</para></listitem>
+ </varlistentry>
+
+ <xi:include href="standard-options.xml" xpointer="help" />
+ <xi:include href="standard-options.xml" xpointer="version" />
+ </variablelist>
+ </refsect2>
+
+ <refsect2>
+ <title>Options that duplicate kernel command line settings</title>
+
+ <para>Those options correspond directly to options listed above in "Kernel Command Line". Both forms
+ may be used equivalently for the system manager, but it is recommended to use the forms listed above in
+ this context, because they are properly namespaced. When an option is specified both on the kernel
+ command line, and as a normal command line argument, the latter has higher precedence.</para>
+
+ <para>When <command>systemd</command> is used a user manager, the kernel command line is ignored and
+ the options described are understood. Nevertheless, <command>systemd</command> is usually started in
+ this mode through the
+ <citerefentry><refentrytitle>user@.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ service, which is shared between all users, and it may be more convenient to use configuration files to
+ modify settings, see
+ <citerefentry><refentrytitle>systemd-user.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ or a drop-in that specifies one of the environment variables listed above in "Environment, see
+ <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
+
+ <variablelist>
+ <varlistentry>
+ <term><option>--unit=</option></term>
+
+ <listitem><para>Set default unit to activate on startup. If not specified, defaults to
+ <filename>default.target</filename>. See <varname>systemd.unit=</varname> above.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--dump-core</option></term>
+
+ <listitem><para>Enable core dumping on crash. This switch has no effect when running as user
+ instance. Same as <varname>systemd.dump_core=</varname> above.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--crash-vt=</option><replaceable>VT</replaceable></term>
+
+ <listitem><para>Switch to a specific virtual console (VT) on crash. This switch has no effect when
+ running as user instance. Same as <varname>systemd.crash_chvt=</varname> above (but not the
+ different spelling!).</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--crash-shell</option></term>
+
+ <listitem><para>Run a shell on crash. This switch has no effect when running as user instance. See
+ <varname>systemd.crash_shell=</varname> above.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--crash-reboot</option></term>
+
+ <listitem><para>Automatically reboot the system on crash. This switch has no effect when running as
+ user instance. See <varname>systemd.crash_reboot</varname> above.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--confirm-spawn</option></term>
+
+ <listitem><para>Ask for confirmation when spawning processes. This switch has no effect when run as
+ user instance. See <varname>systemd.confirm_spawn</varname> above.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--show-status</option></term>
+
+ <listitem><para>Show terse unit status information is shown on the console during boot-up and
+ shutdown. See <varname>systemd.show_status</varname> above.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--log-target=</option></term>
+
+ <listitem><para>Set log target. See <varname>systemd.log_target</varname> above.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--log-level=</option></term>
+
+ <listitem><para>Set log level. See <varname>systemd.log_level</varname> above.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--log-color</option></term>
+
+ <listitem><para>Highlight important log messages. See <varname>systemd.log_color</varname> above.
+ </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--log-location</option></term>
+
+ <listitem><para>Include code location in log messages. See <varname>systemd.log_location</varname>
+ above.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--machine-id=</option></term>
+
+ <listitem><para>Override the machine-id set on the hard drive. See
+ <varname>systemd.machine_id=</varname> above.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--service-watchdogs</option></term>
+
+ <listitem><para>Globally enable/disable all service watchdog timeouts and emergency actions. See
+ <varname>systemd.service_watchdogs</varname> above.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--default-standard-output=</option></term>
+ <term><option>--default-standard-error=</option></term>
+
+ <listitem><para>Sets the default output or error output for all services and sockets,
+ respectively. See <varname>systemd.default_standard_output=</varname> and
+ <varname>systemd.default_standard_error=</varname> above.</para></listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect2>
+ </refsect1>
+
<refsect1>
<title>Sockets and FIFOs</title>
projects / thirdparty / systemd.git / commitdiff
