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diff --git a/man/systemd.xml b/man/systemd.xml new file mode 100644 index 0000000000..7b3d265b8d --- /dev/null +++ b/man/systemd.xml @@ -0,0 +1,1272 @@ +<?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"> + + <refentryinfo> + <title>systemd</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</refentrytitle> + <manvolnum>1</manvolnum> + </refmeta> + + <refnamediv> + <refname>systemd</refname> + <refname>init</refname> + <refpurpose>systemd system and service manager</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <cmdsynopsis> + <command>systemd <arg choice="opt" rep="repeat">OPTIONS</arg></command> + </cmdsynopsis> + <cmdsynopsis> + <command>init <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="req">COMMAND</arg></command> + </cmdsynopsis> + </refsynopsisdiv> + + <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>When run as system instance, systemd interprets + the configuration file + <filename>system.conf</filename>, otherwise + <filename>user.conf</filename>. See + <citerefentry><refentrytitle>systemd.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry> + for more information.</para> + </refsect1> + + <refsect1> + <title>Options</title> + + <para>The following options are understood:</para> + + <variablelist> + <varlistentry> + <term><option>-h</option></term> + <term><option>--help</option></term> + + <listitem><para>Prints a short help + text and exits.</para></listitem> + </varlistentry> + <varlistentry> + <term><option>--version</option></term> + + <listitem><para>Prints a systemd version + identifier and exits.</para></listitem> + </varlistentry> + <varlistentry> + <term><option>--test</option></term> + + <listitem><para>Determine startup + sequence, dump it and exit. This is an + option useful for debugging + only.</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>--introspect=</option></term> + + <listitem><para>Extract D-Bus + interface introspection data. This is + mostly useful at install time + to generate data suitable for the + D-Bus interfaces + repository. Optionally the interface + name for the introspection data may be + specified. If omitted, the + introspection data for all interfaces + is dumped.</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>For <option>--system</option>, + tell systemd to run a + system instance, even if the process ID is + not 1, i.e. systemd is not run as init process. + <option>--user</option> does the opposite, + running a user instance even if the process + ID is 1. + Normally it should not be necessary to + pass these options, as systemd + automatically detects the mode it is + started in. These options are hence of + little use except for debugging. Note + that it is not supported booting and + maintaining a full system with systemd + running in <option>--system</option> + mode, but PID not 1. In practice, + passing <option>--system</option> explicitly is + only useful in conjunction with + <option>--test</option>.</para></listitem> + </varlistentry> + <varlistentry> + <term><option>--dump-core</option></term> + + <listitem><para>Dump core on + crash. This switch has no effect when + run as user + instance.</para></listitem> + </varlistentry> + <varlistentry> + <term><option>--crash-shell</option></term> + + <listitem><para>Run shell on + crash. This switch has no effect when + run as user + instance.</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>Show terse service + status information while booting. This + switch has no effect when run as user + instance. Takes a boolean argument + which may be omitted which is + interpreted as + <option>true</option>.</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>syslog</option>, + <option>kmsg</option>, + <option>journal-or-kmsg</option>, + <option>syslog-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><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>syslog</option>, + <option>syslog+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> + </variablelist> + </refsect1> + + <refsect1> + <title>Concepts</title> + + <para>systemd provides a dependency system between + various entities called "units". Units encapsulate + various objects that are relevant for system boot-up + and maintenance. The majority of units are configured + in unit configuration files, whose syntax and basic + set of options is described in + <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>, + however some are created automatically from other + configuration or dynamically from system state. Units + may be 'active' (meaning started, bound, plugged in, + ... depending on the unit type, see below), or + 'inactive' (meaning stopped, unbound, unplugged, ...), + as well as in the process of being activated or + deactivated, i.e. between the two states (these states + are called 'activating', 'deactivating'). A special + 'failed' state is available as well which is very + similar to 'inactive' and is entered when the service + failed in some way (process returned error code on + exit, or crashed, or an operation timed out). If this + state is entered the cause will be logged, for later + reference. Note that the various unit types may have a + number of additional substates, which are mapped to + the five generalized unit states described + here.</para> + + <para>The following unit types are available:</para> + + <orderedlist> + <listitem><para>Service units, which control + daemons and the processes they consist of. For + details see + <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> + + <listitem><para>Socket units, which + encapsulate local IPC or network sockets in + the system, useful for socket-based + activation. For details about socket units see + <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>, + for details on socket-based activation and + other forms of activation, see + <citerefentry><refentrytitle>daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para></listitem> + + <listitem><para>Target units are useful to + group units, or provide well-known + synchronization points during boot-up, see + <citerefentry><refentrytitle>systemd.target</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> + + <listitem><para>Device units expose kernel + devices in systemd and may be used to + implement device-based activation. For details + see + <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> + + <listitem><para>Mount units control mount + points in the file system, for details see + <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> + + <listitem><para>Automount units provide + automount capabilities, for on-demand mounting + of file systems as well as parallelized + boot-up. See + <citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> + + <listitem><para>Snapshot units can be used to + temporarily save the state of the set of + systemd units, which later may be restored by + activating the saved snapshot unit. For more + information see + <citerefentry><refentrytitle>systemd.snapshot</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> + + <listitem><para>Timer units are useful for + triggering activation of other units based on + timers. You may find details in + <citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> + + <listitem><para>Swap units are very similar to + mount units and encapsulate memory swap + partitions or files of the operating + system. They are described in <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> + + <listitem><para>Path units may be used + to activate other services when file system + objects change or are modified. See + <citerefentry><refentrytitle>systemd.path</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> + + </orderedlist> + + <para>Units are named as their configuration + files. Some units have special semantics. A detailed + list is available in + <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para> + + <para>systemd knows various kinds of dependencies, + including positive and negative requirement + dependencies (i.e. <varname>Requires=</varname> and + <varname>Conflicts=</varname>) as well as ordering + dependencies (<varname>After=</varname> and + <varname>Before=</varname>). NB: ordering and + requirement dependencies are orthogonal. If only a + requirement dependency exists between two units + (e.g. <filename>foo.service</filename> requires + <filename>bar.service</filename>), but no ordering + dependency (e.g. <filename>foo.service</filename> + after <filename>bar.service</filename>) and both are + requested to start, they will be started in + parallel. It is a common pattern that both requirement + and ordering dependencies are placed between two + units. Also note that the majority of dependencies are + implicitly created and maintained by systemd. In most + cases it should be unnecessary to declare additional + dependencies manually, however it is possible to do + this.</para> + + <para>Application programs and units (via + dependencies) may request state changes of units. In + systemd, these requests are encapsulated as 'jobs' and + maintained in a job queue. Jobs may succeed or can + fail, their execution is ordered based on the ordering + dependencies of the units they have been scheduled + for.</para> + + <para>On boot systemd activates the target unit + <filename>default.target</filename> whose job is to + activate on-boot services and other on-boot units by + pulling them in via dependencies. Usually the unit + name is just an alias (symlink) for either + <filename>graphical.target</filename> (for + fully-featured boots into the UI) or + <filename>multi-user.target</filename> (for limited + console-only boots for use in embedded or server + environments, or similar; a subset of + graphical.target). However it is at the discretion of + the administrator to configure it as an alias to any + other target unit. See + <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry> + for details about these target units.</para> + + <para>Processes systemd spawns are placed in + individual Linux control groups named after the unit + which they belong to in the private systemd + hierarchy. (see <ulink + url="http://www.kernel.org/doc/Documentation/cgroups/cgroups.txt">cgroups.txt</ulink> + for more information about control groups, or short + "cgroups"). systemd uses this to effectively keep + track of processes. Control group information is + maintained in the kernel, and is accessible via the + file system hierarchy (beneath + <filename>/sys/fs/cgroup/systemd/</filename>), or in tools + such as + <citerefentry><refentrytitle>ps</refentrytitle><manvolnum>1</manvolnum></citerefentry> + (<command>ps xawf -eo pid,user,cgroup,args</command> + is particularly useful to list all processes and the + systemd units they belong to.).</para> + + <para>systemd is compatible with the SysV init system + to a large degree: SysV init scripts are supported and + simply read as an alternative (though limited) + configuration file format. The SysV + <filename>/dev/initctl</filename> interface is + provided, and compatibility implementations of the + various SysV client tools are available. In addition to + that, various established Unix functionality such as + <filename>/etc/fstab</filename> or the + <filename>utmp</filename> database are + supported.</para> + + <para>systemd has a minimal transaction system: if a + unit is requested to start up or shut down it will add + it and all its dependencies to a temporary + transaction. Then, it will verify if the transaction + is consistent (i.e. whether the ordering of all units + is cycle-free). If it is not, systemd will try to fix + it up, and removes non-essential jobs from the + transaction that might remove the loop. Also, systemd + tries to suppress non-essential jobs in the + transaction that would stop a running service. Finally + it is checked whether the jobs of the transaction + contradict jobs that have already been queued, and + optionally the transaction is aborted then. If all + worked out and the transaction is consistent and + minimized in its impact it is merged with all already + outstanding jobs and added to the run + queue. Effectively this means that before executing a + requested operation, systemd will verify that it makes + sense, fixing it if possible, and only failing if it + really cannot work.</para> + + <para>Systemd contains native implementations of + various tasks that need to be executed as part of the + boot process. For example, it sets the host name or + configures the loopback network device. It also sets + up and mounts various API file systems, such as + <filename>/sys</filename> or + <filename>/proc</filename>.</para> + + <para>For more information about the concepts and + ideas behind systemd please refer to the <ulink + url="http://0pointer.de/blog/projects/systemd.html">Original + Design Document</ulink>.</para> + + <para>Note that some but not all interfaces provided + by systemd are covered by the <ulink + url="http://www.freedesktop.org/wiki/Software/systemd/InterfaceStabilityPromise">Interface + Stability Promise</ulink>.</para> + + <para>Units may be generated dynamically at boot and + system manager reload time, for example based on other + configuration files or parameters passed on the kernel + command line. For details see the <ulink + url="http://www.freedesktop.org/wiki/Software/systemd/Generators">Generators + Specification</ulink>.</para> + + <para>Systems which invoke systemd in a container + or initrd environment should implement the + <ulink + url="http://www.freedesktop.org/wiki/Software/systemd/ContainerInterface">Container + Interface</ulink> or <ulink + url="http://www.freedesktop.org/wiki/Software/systemd/InitrdInterface">initrd + Interface</ulink> specifications, respectively.</para> + </refsect1> + + <refsect1> + <title>Directories</title> + + <variablelist> + <varlistentry> + <term>System unit directories</term> + + <listitem><para>The systemd system + manager reads unit configuration from + various directories. Packages that + want to install unit files shall place + them in the directory returned by + <command>pkg-config systemd + --variable=systemdsystemunitdir</command>. Other + directories checked are + <filename>/usr/local/lib/systemd/system</filename> + and + <filename>/usr/lib/systemd/system</filename>. User + configuration always takes + precedence. <command>pkg-config + systemd + --variable=systemdsystemconfdir</command> + returns the path of the system + configuration directory. Packages + should alter the content of these + directories only with the + <command>enable</command> and + <command>disable</command> commands of + the + <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> + tool.</para></listitem> + </varlistentry> + </variablelist> + + <variablelist> + <varlistentry> + <term>User unit directories</term> + + <listitem><para>Similar rules apply + for the user unit + directories. However, here the <ulink + url="http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html">XDG + Base Directory specification</ulink> + is followed to find + units. Applications should place their + unit files in the directory returned + by <command>pkg-config systemd + --variable=systemduserunitdir</command>. Global + configuration is done in the directory + reported by <command>pkg-config + systemd + --variable=systemduserconfdir</command>. The + <command>enable</command> and + <command>disable</command> commands of + the + <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> + tool can handle both global (i.e. for + all users) and private (for one user) + enabling/disabling of + units.</para></listitem> + </varlistentry> + </variablelist> + + <variablelist> + <varlistentry> + <term>SysV init scripts directory</term> + + <listitem><para>The location of the + SysV init script directory varies + between distributions. If systemd + cannot find a native unit file for a + requested service, it will look for a + SysV init script of the same name + (with the + <filename>.service</filename> suffix + removed).</para></listitem> + </varlistentry> + </variablelist> + + <variablelist> + <varlistentry> + <term>SysV runlevel link farm directory</term> + + <listitem><para>The location of the + SysV runlevel link farm directory + varies between distributions. systemd + will take the link farm into account + when figuring out whether a service + shall be enabled. Note that a service + unit with a native unit configuration + file cannot be started by activating it + in the SysV runlevel link + farm.</para></listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>Signals</title> + + <variablelist> + <varlistentry> + <term>SIGTERM</term> + + <listitem><para>Upon receiving this + signal the systemd system manager + serializes its state, reexecutes + itself and deserializes the saved + state again. This is mostly equivalent + to <command>systemctl + daemon-reexec</command>.</para> + + <para>systemd user managers will + start the + <filename>exit.target</filename> unit + when this signal is received. This is + mostly equivalent to + <command>systemctl --user start + exit.target</command>.</para></listitem> + </varlistentry> + + <varlistentry> + <term>SIGINT</term> + + <listitem><para>Upon receiving this + signal the systemd system manager will + start the + <filename>ctrl-alt-del.target</filename> unit. This + is mostly equivalent to + <command>systemctl start + ctl-alt-del.target</command>.</para> + + <para>systemd user managers + treat this signal the same way as + SIGTERM.</para></listitem> + </varlistentry> + + <varlistentry> + <term>SIGWINCH</term> + + <listitem><para>When this signal is + received the systemd system manager + will start the + <filename>kbrequest.target</filename> + unit. This is mostly equivalent to + <command>systemctl start + kbrequest.target</command>.</para> + + <para>This signal is ignored by + systemd user + managers.</para></listitem> + </varlistentry> + + <varlistentry> + <term>SIGPWR</term> + + <listitem><para>When this signal is + received the systemd manager + will start the + <filename>sigpwr.target</filename> + unit. This is mostly equivalent to + <command>systemctl start + sigpwr.target</command>.</para></listitem> + </varlistentry> + + <varlistentry> + <term>SIGUSR1</term> + + <listitem><para>When this signal is + received the systemd manager will try + to reconnect to the D-Bus + bus.</para></listitem> + </varlistentry> + + <varlistentry> + <term>SIGUSR2</term> + + <listitem><para>When this signal is + received the systemd manager will log + its complete state in human readable + form. The data logged is the same as + printed by <command>systemctl + dump</command>.</para></listitem> + </varlistentry> + + <varlistentry> + <term>SIGHUP</term> + + <listitem><para>Reloads the complete + daemon configuration. This is mostly + equivalent to <command>systemctl + daemon-reload</command>.</para></listitem> + </varlistentry> + + <varlistentry> + <term>SIGRTMIN+0</term> + + <listitem><para>Enters default mode, starts the + <filename>default.target</filename> + unit. This is mostly equivalent to + <command>systemctl start + default.target</command>.</para></listitem> + </varlistentry> + + <varlistentry> + <term>SIGRTMIN+1</term> + + <listitem><para>Enters rescue mode, + starts the + <filename>rescue.target</filename> + unit. This is mostly equivalent to + <command>systemctl isolate + rescue.target</command>.</para></listitem> + </varlistentry> + + <varlistentry> + <term>SIGRTMIN+2</term> + + <listitem><para>Enters emergency mode, + starts the + <filename>emergency.service</filename> + unit. This is mostly equivalent to + <command>systemctl isolate + emergency.service</command>.</para></listitem> + </varlistentry> + + <varlistentry> + <term>SIGRTMIN+3</term> + + <listitem><para>Halts the machine, + starts the + <filename>halt.target</filename> + unit. This is mostly equivalent to + <command>systemctl start + halt.target</command>.</para></listitem> + </varlistentry> + + <varlistentry> + <term>SIGRTMIN+4</term> + + <listitem><para>Powers off the machine, + starts the + <filename>poweroff.target</filename> + unit. This is mostly equivalent to + <command>systemctl start + poweroff.target</command>.</para></listitem> + </varlistentry> + + <varlistentry> + <term>SIGRTMIN+5</term> + + <listitem><para>Reboots the machine, + starts the + <filename>reboot.target</filename> + unit. This is mostly equivalent to + <command>systemctl start + reboot.target</command>.</para></listitem> + </varlistentry> + + <varlistentry> + <term>SIGRTMIN+6</term> + + <listitem><para>Reboots the machine via kexec, + starts the + <filename>kexec.target</filename> + unit. This is mostly equivalent to + <command>systemctl start + kexec.target</command>.</para></listitem> + </varlistentry> + + <varlistentry> + <term>SIGRTMIN+13</term> + + <listitem><para>Immediately halts the machine.</para></listitem> + </varlistentry> + + <varlistentry> + <term>SIGRTMIN+14</term> + + <listitem><para>Immediately powers off the machine.</para></listitem> + </varlistentry> + + <varlistentry> + <term>SIGRTMIN+15</term> + + <listitem><para>Immediately reboots the machine.</para></listitem> + </varlistentry> + + <varlistentry> + <term>SIGRTMIN+16</term> + + <listitem><para>Immediately reboots the machine with kexec.</para></listitem> + </varlistentry> + + <varlistentry> + <term>SIGRTMIN+20</term> + + <listitem><para>Enables display of + status messages on the console, as + controlled via + <varname>systemd.show_status=1</varname> + on the kernel command + line.</para></listitem> + </varlistentry> + + <varlistentry> + <term>SIGRTMIN+21</term> + + <listitem><para>Disables display of + status messages on the console, as + controlled via + <varname>systemd.show_status=0</varname> + on the kernel command + line.</para></listitem> + </varlistentry> + + <varlistentry> + <term>SIGRTMIN+22</term> + <term>SIGRTMIN+23</term> + + <listitem><para>Sets the log level to + <literal>debug</literal> + (or <literal>info</literal> on + <literal>SIGRTMIN+23</literal>), as + controlled via + <varname>systemd.log_level=debug</varname> + (or <varname>systemd.log_level=info</varname> + on <literal>SIGRTMIN+23</literal>) on + the kernel command + line.</para></listitem> + </varlistentry> + + <varlistentry> + <term>SIGRTMIN+24</term> + + <listitem><para>Immediately exits the + manager (only available for --user + instances).</para></listitem> + </varlistentry> + + <varlistentry> + <term>SIGRTMIN+26</term> + <term>SIGRTMIN+27</term> + <term>SIGRTMIN+28</term> + <term>SIGRTMIN+29</term> + + <listitem><para>Sets the log level to + <literal>journal-or-kmsg</literal> + (or <literal>console</literal> on + <literal>SIGRTMIN+27</literal>, + <literal>kmsg</literal> on + <literal>SIGRTMIN+28</literal>, + or <literal>syslog-or-kmsg</literal> + on <literal>SIGRTMIN+29</literal>), as + controlled via + <varname>systemd.log_target=journal-or-kmsg</varname> + (or <varname>systemd.log_target=console</varname> + on <literal>SIGRTMIN+27</literal>, + <varname>systemd.log_target=kmsg</varname> + on <literal>SIGRTMIN+28</literal>, + or + <varname>systemd.log_target=syslog-or-kmsg</varname> + on <literal>SIGRTMIN+29</literal>) on + the kernel command + line.</para></listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>Environment</title> + + <variablelist> + <varlistentry> + <term><varname>$SYSTEMD_LOG_LEVEL</varname></term> + <listitem><para>systemd reads the + log level from this environment + variable. This can be overridden with + <option>--log-level=</option>.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>$SYSTEMD_LOG_TARGET</varname></term> + <listitem><para>systemd reads the + log target from this environment + variable. This can be overridden with + <option>--log-target=</option>.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>$SYSTEMD_LOG_COLOR</varname></term> + <listitem><para>Controls whether + systemd highlights important log + messages. This can be overridden with + <option>--log-color=</option>.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>$SYSTEMD_LOG_LOCATION</varname></term> + <listitem><para>Controls whether + systemd prints the code location along + with log messages. This can be + overridden with + <option>--log-location=</option>.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>$XDG_CONFIG_HOME</varname></term> + <term><varname>$XDG_CONFIG_DIRS</varname></term> + <term><varname>$XDG_DATA_HOME</varname></term> + <term><varname>$XDG_DATA_DIRS</varname></term> + + <listitem><para>The systemd user + manager uses these variables in + accordance to the <ulink + url="http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html">XDG + Base Directory specification</ulink> + to find its configuration.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>$SYSTEMD_UNIT_PATH</varname></term> + + <listitem><para>Controls where systemd + looks for unit + files.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>$SYSTEMD_SYSVINIT_PATH</varname></term> + + <listitem><para>Controls where systemd + looks for SysV init scripts.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>$SYSTEMD_SYSVRCND_PATH</varname></term> + + <listitem><para>Controls where systemd + looks for SysV init script runlevel link + farms.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>$LISTEN_PID</varname></term> + <term><varname>$LISTEN_FDS</varname></term> + + <listitem><para>Set by systemd for + supervised processes during + socket-based activation. See + <citerefentry><refentrytitle>sd_listen_fds</refentrytitle><manvolnum>3</manvolnum></citerefentry> + for more information. + </para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>$NOTIFY_SOCKET</varname></term> + + <listitem><para>Set by systemd for + supervised processes for status and + start-up completion notification. See + <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry> + for more information. + </para></listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>Kernel Command Line</title> + + <para>When run as system instance systemd parses a + number of kernel command line + arguments<footnote><para>If run inside a Linux + container these arguments may be passed as command + line arguments to systemd itself, next to any of the + command line options listed in the Options section + above. If run outside of Linux containers, these + arguments are parsed from + <filename>/proc/cmdline</filename> + instead.</para></footnote>:</para> + + <variablelist> + <varlistentry> + <term><varname>systemd.unit=</varname></term> + <term><varname>rd.systemd.unit=</varname></term> + + <listitem><para>Overrides the unit to + activate on boot. Defaults to + <filename>default.target</filename>. This + may be used to temporarily boot into a + different boot unit, for example + <filename>rescue.target</filename> or + <filename>emergency.service</filename>. See + <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry> + for details about these units. The + option prefixed with + <literal>rd.</literal> is honored + only in the initial RAM disk (initrd), + while the one that isn't prefixed only + in the main system.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>systemd.dump_core=</varname></term> + + <listitem><para>Takes a boolean + argument. If <option>true</option> + systemd dumps core when it + crashes. Otherwise no core dump is + created. Defaults to + <option>true</option>.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>systemd.crash_shell=</varname></term> + + <listitem><para>Takes a boolean + argument. If <option>true</option> + systemd spawns a shell when it + crashes. Otherwise no shell is + spawned. Defaults to + <option>false</option>, for security + reasons, as the shell is not protected + by any password + authentication.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>systemd.crash_chvt=</varname></term> + + <listitem><para>Takes an integer + argument. If positive systemd + activates the specified virtual + terminal when it crashes. Defaults to + <literal>-1</literal>.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>systemd.confirm_spawn=</varname></term> + + <listitem><para>Takes a boolean + argument. If <option>true</option> + asks for confirmation when spawning + processes. Defaults to + <option>false</option>.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>systemd.show_status=</varname></term> + + <listitem><para>Takes a boolean + argument. If <option>true</option> + shows terse service status updates on + the console during bootup. Defaults to + <option>true</option>, unless + <option>quiet</option> is passed as + kernel command line option in which + case it defaults to + <option>false</option>.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>systemd.log_target=</varname></term> + <term><varname>systemd.log_level=</varname></term> + <term><varname>systemd.log_color=</varname></term> + <term><varname>systemd.log_location=</varname></term> + + <listitem><para>Controls log output, + with the same effect as the + <varname>$SYSTEMD_LOG_TARGET</varname>, <varname>$SYSTEMD_LOG_LEVEL</varname>, <varname>$SYSTEMD_LOG_COLOR</varname>, <varname>$SYSTEMD_LOG_LOCATION</varname> + environment variables described above.</para></listitem> + </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> + </varlistentry> + + <varlistentry> + <term><varname>systemd.setenv=</varname></term> + + <listitem><para>Takes a string + argument in the form + VARIABLE=VALUE. May be used to set + environment variables for the init + process and all its children at boot + time. May be used more than once to + set multiple variables. If the equal + sign and variable are missing it unsets + an environment variable which might be + passed in from the initial ram + disk.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>quiet</varname></term> + + <listitem><para>If passed turns off + status output at boot, much like + <varname>systemd.show_status=false</varname> + would. Note that this option is also + read by the kernel itself and disables + kernel log output to the + kernel. Passing this option hence + turns off the usual output from both + the system manager and the + kernel.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>emergency</varname></term> + + <listitem><para>Boot into emergency + mode. This is equivalent to + <varname>systemd.unit=emergency.target</varname> + and provided for compatibility + reasons and to be easier to type.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>single</varname></term> + <term><varname>s</varname></term> + <term><varname>S</varname></term> + <term><varname>1</varname></term> + + <listitem><para>Boot into rescue + mode. This is equivalent to + <varname>systemd.unit=rescue.target</varname> + and provided for compatibility reasons + and to be easier to + type.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>2</varname></term> + <term><varname>3</varname></term> + <term><varname>4</varname></term> + <term><varname>5</varname></term> + + <listitem><para>Boot into the + specified legacy SysV runlevel. These + are equivalent to + <varname>systemd.unit=runlevel2.target</varname>, + <varname>systemd.unit=runlevel3.target</varname>, + <varname>systemd.unit=runlevel4.target</varname>, + and <varname>systemd.unit=runlevel5.target</varname>, respectively, + and provided for compatibility reasons + and to be easier to + type.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>locale.LANG=</varname></term> + <term><varname>locale.LANGUAGE=</varname></term> + <term><varname>locale.LC_CTYPE=</varname></term> + <term><varname>locale.LC_NUMERIC=</varname></term> + <term><varname>locale.LC_TIME=</varname></term> + <term><varname>locale.LC_COLLATE=</varname></term> + <term><varname>locale.LC_MONETARY=</varname></term> + <term><varname>locale.LC_MESSAGES=</varname></term> + <term><varname>locale.LC_PAPER=</varname></term> + <term><varname>locale.LC_NAME=</varname></term> + <term><varname>locale.LC_ADDRESS=</varname></term> + <term><varname>locale.LC_TELEPHONE=</varname></term> + <term><varname>locale.LC_MEASUREMENT=</varname></term> + <term><varname>locale.LC_IDENTIFICATION=</varname></term> + + <listitem><para>Set the system locale + to use. This overrides the settings in + <filename>/etc/locale.conf</filename>. For + more information see + <citerefentry><refentrytitle>locale.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry> + and + <citerefentry><refentrytitle>locale</refentrytitle><manvolnum>7</manvolnum></citerefentry>. + </para></listitem> + </varlistentry> + </variablelist> + + <para>For other kernel command line parameters + understood by components of the core OS, please refer + to + <citerefentry><refentrytitle>kernel-command-line</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para> + </refsect1> + + <refsect1> + <title>Sockets and FIFOs</title> + + <variablelist> + <varlistentry> + <term><filename>/run/systemd/notify</filename></term> + + <listitem><para>Daemon status + notification socket. This is an + AF_UNIX datagram socket and is used to + implement the daemon notification + logic as implemented by + <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para></listitem> + + </varlistentry> + + <varlistentry> + <term><filename>/run/systemd/shutdownd</filename></term> + + <listitem><para>Used internally by the + <citerefentry><refentrytitle>shutdown</refentrytitle><manvolnum>8</manvolnum></citerefentry> + tool to implement delayed + shutdowns. This is an AF_UNIX datagram + socket.</para></listitem> + </varlistentry> + + <varlistentry> + <term><filename>/run/systemd/private</filename></term> + + <listitem><para>Used internally as + communication channel between + <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> + and the systemd process. This is an + AF_UNIX stream socket. This interface + is private to systemd and should not + be used in external + projects.</para></listitem> + </varlistentry> + + <varlistentry> + <term><filename>/dev/initctl</filename></term> + + <listitem><para>Limited compatibility + support for the SysV client interface, + as implemented by the + <filename>systemd-initctl.service</filename> + unit. This is a named pipe in the file + system. This interface is obsolete and + should not be used in new + applications.</para></listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>See Also</title> + <para> + <citerefentry><refentrytitle>systemd.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>, + <citerefentry><refentrytitle>locale.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd-notify</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>5</manvolnum></citerefentry>, + <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>kernel-command-line</refentrytitle><manvolnum>7</manvolnum></citerefentry>, + <citerefentry><refentrytitle>bootup</refentrytitle><manvolnum>7</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> |