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514094f9 | 1 | <?xml version='1.0'?> |
3a54a157 | 2 | <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" |
12b42c76 | 3 | "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> |
db9ecf05 | 4 | <!-- SPDX-License-Identifier: LGPL-2.1-or-later --> |
9e632bf7 | 5 | |
dfdebb1b | 6 | <refentry id="systemd" |
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7 | xmlns:xi="http://www.w3.org/2001/XInclude"> |
8 | ||
9 | <refentryinfo> | |
10 | <title>systemd</title> | |
11 | <productname>systemd</productname> | |
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12 | </refentryinfo> |
13 | ||
14 | <refmeta> | |
15 | <refentrytitle>systemd</refentrytitle> | |
16 | <manvolnum>1</manvolnum> | |
17 | </refmeta> | |
18 | ||
19 | <refnamediv> | |
20 | <refname>systemd</refname> | |
21 | <refname>init</refname> | |
22 | <refpurpose>systemd system and service manager</refpurpose> | |
23 | </refnamediv> | |
24 | ||
25 | <refsynopsisdiv> | |
26 | <cmdsynopsis> | |
b57b372a | 27 | <command>/usr/lib/systemd/systemd</command> |
770c4777 | 28 | <arg choice="opt" rep="repeat">OPTIONS</arg> |
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29 | </cmdsynopsis> |
30 | <cmdsynopsis> | |
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31 | <command>init</command> |
32 | <arg choice="opt" rep="repeat">OPTIONS</arg> | |
33 | <arg choice="req">COMMAND</arg> | |
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34 | </cmdsynopsis> |
35 | </refsynopsisdiv> | |
36 | ||
37 | <refsect1> | |
38 | <title>Description</title> | |
39 | ||
c035f376 | 40 | <para>systemd is a system and service manager for Linux operating systems. When run as first process on |
11fcfc53 | 41 | boot (as PID 1), it acts as init system that brings up and maintains userspace services. Separate |
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42 | instances are started for logged-in users to start their services.</para> |
43 | ||
44 | <para><command>systemd</command> is usually not invoked directly by the user, but is installed as the | |
45 | <filename>/sbin/init</filename> symlink and started during early boot. The user manager instances are | |
46 | started automatically through the | |
47 | <citerefentry><refentrytitle>user@.service</refentrytitle><manvolnum>5</manvolnum></citerefentry> | |
48 | service.</para> | |
49 | ||
50 | <para>For compatibility with SysV, if the binary is called as <command>init</command> and is not the | |
51 | first process on the machine (PID is not 1), it will execute <command>telinit</command> and pass all | |
52 | command line arguments unmodified. That means <command>init</command> and <command>telinit</command> are | |
53 | mostly equivalent when invoked from normal login sessions. See | |
54 | <citerefentry><refentrytitle>telinit</refentrytitle><manvolnum>8</manvolnum></citerefentry> for more | |
55 | information.</para> | |
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56 | |
57 | <para>When run as a system instance, systemd interprets the | |
58 | configuration file <filename>system.conf</filename> and the files | |
59 | in <filename>system.conf.d</filename> directories; when run as a | |
60 | user instance, systemd interprets the configuration file | |
61 | <filename>user.conf</filename> and the files in | |
62 | <filename>user.conf.d</filename> directories. See | |
63 | <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry> | |
64 | for more information.</para> | |
65 | </refsect1> | |
66 | ||
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67 | <refsect1> |
68 | <title>Concepts</title> | |
69 | ||
70 | <para>systemd provides a dependency system between various | |
19f0cf65 | 71 | entities called "units" of 11 different types. Units encapsulate |
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72 | various objects that are relevant for system boot-up and |
73 | maintenance. The majority of units are configured in unit | |
74 | configuration files, whose syntax and basic set of options is | |
75 | described in | |
76 | <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
a814eae7 | 77 | however some are created automatically from other configuration |
78 | files, dynamically from system state or programmatically at runtime. | |
1eecafb8 | 79 | Units may be "active" (meaning started, bound, plugged in, …, |
798d3a52 | 80 | depending on the unit type, see below), or "inactive" (meaning |
1eecafb8 | 81 | stopped, unbound, unplugged, …), as well as in the process of |
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82 | being activated or deactivated, i.e. between the two states (these |
83 | states are called "activating", "deactivating"). A special | |
84 | "failed" state is available as well, which is very similar to | |
85 | "inactive" and is entered when the service failed in some way | |
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86 | (process returned error code on exit, or crashed, an operation |
87 | timed out, or after too many restarts). If this state is entered, | |
88 | the cause will be logged, for later reference. Note that the | |
89 | various unit types may have a number of additional substates, | |
90 | which are mapped to the five generalized unit states described | |
91 | here.</para> | |
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92 | |
93 | <para>The following unit types are available:</para> | |
94 | ||
95 | <orderedlist> | |
96 | <listitem><para>Service units, which start and control daemons | |
b938cb90 | 97 | and the processes they consist of. For details, see |
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98 | <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> |
99 | ||
100 | <listitem><para>Socket units, which encapsulate local IPC or | |
101 | network sockets in the system, useful for socket-based | |
b938cb90 | 102 | activation. For details about socket units, see |
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103 | <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>, |
104 | for details on socket-based activation and other forms of | |
105 | activation, see | |
106 | <citerefentry><refentrytitle>daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para></listitem> | |
107 | ||
108 | <listitem><para>Target units are useful to group units, or | |
109 | provide well-known synchronization points during boot-up, see | |
110 | <citerefentry><refentrytitle>systemd.target</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> | |
111 | ||
112 | <listitem><para>Device units expose kernel devices in systemd | |
113 | and may be used to implement device-based activation. For | |
b938cb90 | 114 | details, see |
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115 | <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> |
116 | ||
117 | <listitem><para>Mount units control mount points in the file | |
118 | system, for details see | |
119 | <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> | |
120 | ||
121 | <listitem><para>Automount units provide automount capabilities, | |
122 | for on-demand mounting of file systems as well as parallelized | |
123 | boot-up. See | |
124 | <citerefentry><refentrytitle>systemd.automount</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> | |
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125 | |
126 | <listitem><para>Timer units are useful for triggering activation | |
127 | of other units based on timers. You may find details in | |
128 | <citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> | |
129 | ||
130 | <listitem><para>Swap units are very similar to mount units and | |
131 | encapsulate memory swap partitions or files of the operating | |
132 | system. They are described in | |
133 | <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> | |
134 | ||
135 | <listitem><para>Path units may be used to activate other | |
136 | services when file system objects change or are modified. See | |
137 | <citerefentry><refentrytitle>systemd.path</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> | |
138 | ||
139 | <listitem><para>Slice units may be used to group units which | |
140 | manage system processes (such as service and scope units) in a | |
141 | hierarchical tree for resource management purposes. See | |
142 | <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> | |
143 | ||
144 | <listitem><para>Scope units are similar to service units, but | |
145 | manage foreign processes instead of starting them as well. See | |
146 | <citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> | |
147 | ||
148 | </orderedlist> | |
149 | ||
150 | <para>Units are named as their configuration files. Some units | |
151 | have special semantics. A detailed list is available in | |
152 | <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para> | |
153 | ||
154 | <para>systemd knows various kinds of dependencies, including | |
155 | positive and negative requirement dependencies (i.e. | |
156 | <varname>Requires=</varname> and <varname>Conflicts=</varname>) as | |
157 | well as ordering dependencies (<varname>After=</varname> and | |
158 | <varname>Before=</varname>). NB: ordering and requirement | |
159 | dependencies are orthogonal. If only a requirement dependency | |
160 | exists between two units (e.g. <filename>foo.service</filename> | |
161 | requires <filename>bar.service</filename>), but no ordering | |
162 | dependency (e.g. <filename>foo.service</filename> after | |
163 | <filename>bar.service</filename>) and both are requested to start, | |
164 | they will be started in parallel. It is a common pattern that both | |
165 | requirement and ordering dependencies are placed between two | |
166 | units. Also note that the majority of dependencies are implicitly | |
167 | created and maintained by systemd. In most cases, it should be | |
168 | unnecessary to declare additional dependencies manually, however | |
169 | it is possible to do this.</para> | |
170 | ||
171 | <para>Application programs and units (via dependencies) may | |
172 | request state changes of units. In systemd, these requests are | |
173 | encapsulated as 'jobs' and maintained in a job queue. Jobs may | |
174 | succeed or can fail, their execution is ordered based on the | |
175 | ordering dependencies of the units they have been scheduled | |
176 | for.</para> | |
177 | ||
178 | <para>On boot systemd activates the target unit | |
179 | <filename>default.target</filename> whose job is to activate | |
180 | on-boot services and other on-boot units by pulling them in via | |
b938cb90 | 181 | dependencies. Usually, the unit name is just an alias (symlink) for |
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182 | either <filename>graphical.target</filename> (for fully-featured |
183 | boots into the UI) or <filename>multi-user.target</filename> (for | |
184 | limited console-only boots for use in embedded or server | |
185 | environments, or similar; a subset of graphical.target). However, | |
186 | it is at the discretion of the administrator to configure it as an | |
187 | alias to any other target unit. See | |
188 | <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry> | |
189 | for details about these target units.</para> | |
190 | ||
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191 | <para>On first boot, <command>systemd</command> will enable or disable units according to preset policy. |
192 | See <citerefentry><refentrytitle>systemd.preset</refentrytitle><manvolnum>5</manvolnum></citerefentry> | |
193 | and "First Boot Semantics" in | |
194 | <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para> | |
195 | ||
196 | <para>systemd only keeps a minimal set of units loaded into memory. Specifically, the only units that are | |
197 | kept loaded into memory are those for which at least one of the following conditions is true:</para> | |
e5b62c9b LP |
198 | |
199 | <orderedlist> | |
05d4db20 | 200 | <listitem><para>It is in an active, activating, deactivating or failed state (i.e. in any unit state except for <literal>inactive</literal>)</para></listitem> |
e5b62c9b | 201 | <listitem><para>It has a job queued for it</para></listitem> |
42a739a0 | 202 | <listitem><para>It is a dependency of at least one other unit that is loaded into memory</para></listitem> |
e5b62c9b LP |
203 | <listitem><para>It has some form of resource still allocated (e.g. a service unit that is inactive but for which |
204 | a process is still lingering that ignored the request to be terminated)</para></listitem> | |
205 | <listitem><para>It has been pinned into memory programmatically by a D-Bus call</para></listitem> | |
206 | </orderedlist> | |
207 | ||
208 | <para>systemd will automatically and implicitly load units from disk — if they are not loaded yet — as soon as | |
209 | operations are requested for them. Thus, in many respects, the fact whether a unit is loaded or not is invisible to | |
210 | clients. Use <command>systemctl list-units --all</command> to comprehensively list all units currently loaded. Any | |
211 | unit for which none of the conditions above applies is promptly unloaded. Note that when a unit is unloaded from | |
212 | memory its accounting data is flushed out too. However, this data is generally not lost, as a journal log record | |
213 | is generated declaring the consumed resources whenever a unit shuts down.</para> | |
214 | ||
6d48c7cf LP |
215 | <para>Processes systemd spawns are placed in individual Linux control groups named after the unit which |
216 | they belong to in the private systemd hierarchy. (see <ulink | |
217 | url="https://docs.kernel.org/admin-guide/cgroup-v2.html">Control Groups v2</ulink> for more information | |
218 | about control groups, or short "cgroups"). systemd uses this to effectively keep track of | |
219 | processes. Control group information is maintained in the kernel, and is accessible via the file system | |
220 | hierarchy (beneath <filename>/sys/fs/cgroup/</filename>), or in tools such as <citerefentry | |
221 | project='man-pages'><refentrytitle>systemd-cgls</refentrytitle><manvolnum>1</manvolnum></citerefentry> or | |
222 | <citerefentry | |
223 | project='man-pages'><refentrytitle>ps</refentrytitle><manvolnum>1</manvolnum></citerefentry> (<command>ps | |
224 | xawf -eo pid,user,cgroup,args</command> is particularly useful to list all processes and the systemd | |
225 | units they belong to.).</para> | |
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226 | |
227 | <para>systemd is compatible with the SysV init system to a large | |
228 | degree: SysV init scripts are supported and simply read as an | |
229 | alternative (though limited) configuration file format. The SysV | |
230 | <filename>/dev/initctl</filename> interface is provided, and | |
231 | compatibility implementations of the various SysV client tools are | |
232 | available. In addition to that, various established Unix | |
233 | functionality such as <filename>/etc/fstab</filename> or the | |
234 | <filename>utmp</filename> database are supported.</para> | |
235 | ||
236 | <para>systemd has a minimal transaction system: if a unit is | |
237 | requested to start up or shut down it will add it and all its | |
238 | dependencies to a temporary transaction. Then, it will verify if | |
239 | the transaction is consistent (i.e. whether the ordering of all | |
240 | units is cycle-free). If it is not, systemd will try to fix it up, | |
241 | and removes non-essential jobs from the transaction that might | |
242 | remove the loop. Also, systemd tries to suppress non-essential | |
243 | jobs in the transaction that would stop a running service. Finally | |
244 | it is checked whether the jobs of the transaction contradict jobs | |
245 | that have already been queued, and optionally the transaction is | |
246 | aborted then. If all worked out and the transaction is consistent | |
247 | and minimized in its impact it is merged with all already | |
248 | outstanding jobs and added to the run queue. Effectively this | |
249 | means that before executing a requested operation, systemd will | |
250 | verify that it makes sense, fixing it if possible, and only | |
251 | failing if it really cannot work.</para> | |
92e29d82 | 252 | |
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253 | <para>Note that transactions are generated independently of a unit's |
254 | state at runtime, hence, for example, if a start job is requested on an | |
255 | already started unit, it will still generate a transaction and wake up any | |
256 | inactive dependencies (and cause propagation of other jobs as per the | |
257 | defined relationships). This is because the enqueued job is at the time of | |
258 | execution compared to the target unit's state and is marked successful and | |
259 | complete when both satisfy. However, this job also pulls in other | |
260 | dependencies due to the defined relationships and thus leads to, in our | |
5ec7a994 | 261 | example, start jobs for any of those inactive units getting queued as |
05d4db20 | 262 | well.</para> |
798d3a52 | 263 | |
f95b0be7 | 264 | <para>systemd contains native implementations of various tasks |
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265 | that need to be executed as part of the boot process. For example, |
266 | it sets the hostname or configures the loopback network device. It | |
267 | also sets up and mounts various API file systems, such as | |
3b121157 | 268 | <filename>/sys/</filename> or <filename>/proc/</filename>.</para> |
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269 | |
270 | <para>For more information about the concepts and | |
271 | ideas behind systemd, please refer to the | |
dc7e580e | 272 | <ulink url="https://0pointer.de/blog/projects/systemd.html">Original Design Document</ulink>.</para> |
798d3a52 | 273 | |
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274 | <para>Note that some but not all interfaces provided by systemd are covered by the |
275 | <ulink url="https://systemd.io/PORTABILITY_AND_STABILITY/">Interface Portability and Stability Promise</ulink>.</para> | |
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276 | |
277 | <para>Units may be generated dynamically at boot and system | |
278 | manager reload time, for example based on other configuration | |
b938cb90 | 279 | files or parameters passed on the kernel command line. For details, see |
b1c1a519 | 280 | <citerefentry><refentrytitle>systemd.generator</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para> |
798d3a52 | 281 | |
3031660c | 282 | <para>The D-Bus API of <command>systemd</command> is described in |
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283 | <citerefentry><refentrytitle>org.freedesktop.systemd1</refentrytitle><manvolnum>5</manvolnum></citerefentry> |
284 | and | |
285 | <citerefentry><refentrytitle>org.freedesktop.LogControl1</refentrytitle><manvolnum>5</manvolnum></citerefentry>. | |
286 | </para> | |
3031660c | 287 | |
53dc5fbc | 288 | <para>Systems which invoke systemd in a container or initrd environment should implement the <ulink |
f856778b | 289 | url="https://systemd.io/CONTAINER_INTERFACE">Container Interface</ulink> or |
290 | <ulink url="https://systemd.io/INITRD_INTERFACE/">initrd Interface</ulink> | |
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291 | specifications, respectively.</para> |
292 | </refsect1> | |
293 | ||
294 | <refsect1> | |
295 | <title>Directories</title> | |
296 | ||
297 | <variablelist> | |
298 | <varlistentry> | |
299 | <term>System unit directories</term> | |
300 | ||
301 | <listitem><para>The systemd system manager reads unit | |
302 | configuration from various directories. Packages that want to | |
303 | install unit files shall place them in the directory returned | |
304 | by <command>pkg-config systemd | |
305 | --variable=systemdsystemunitdir</command>. Other directories | |
306 | checked are <filename>/usr/local/lib/systemd/system</filename> | |
12b42c76 | 307 | and <filename>/usr/lib/systemd/system</filename>. User |
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308 | configuration always takes precedence. <command>pkg-config |
309 | systemd --variable=systemdsystemconfdir</command> returns the | |
310 | path of the system configuration directory. Packages should | |
311 | alter the content of these directories only with the | |
312 | <command>enable</command> and <command>disable</command> | |
313 | commands of the | |
314 | <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
315 | tool. Full list of directories is provided in | |
316 | <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. | |
317 | </para></listitem> | |
318 | </varlistentry> | |
319 | </variablelist> | |
320 | ||
321 | <variablelist> | |
322 | <varlistentry> | |
323 | <term>User unit directories</term> | |
324 | ||
325 | <listitem><para>Similar rules apply for the user unit | |
326 | directories. However, here the | |
41d6f3bf | 327 | <ulink url="https://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html">XDG |
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328 | Base Directory specification</ulink> is followed to find |
329 | units. Applications should place their unit files in the | |
330 | directory returned by <command>pkg-config systemd | |
331 | --variable=systemduserunitdir</command>. Global configuration | |
332 | is done in the directory reported by <command>pkg-config | |
333 | systemd --variable=systemduserconfdir</command>. The | |
334 | <command>enable</command> and <command>disable</command> | |
335 | commands of the | |
336 | <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
337 | tool can handle both global (i.e. for all users) and private | |
338 | (for one user) enabling/disabling of units. Full list of | |
339 | directories is provided in | |
340 | <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>. | |
341 | </para></listitem> | |
342 | </varlistentry> | |
343 | </variablelist> | |
344 | ||
345 | <variablelist> | |
346 | <varlistentry> | |
347 | <term>SysV init scripts directory</term> | |
348 | ||
349 | <listitem><para>The location of the SysV init script directory | |
350 | varies between distributions. If systemd cannot find a native | |
351 | unit file for a requested service, it will look for a SysV | |
352 | init script of the same name (with the | |
353 | <filename>.service</filename> suffix | |
354 | removed).</para></listitem> | |
355 | </varlistentry> | |
356 | </variablelist> | |
357 | ||
358 | <variablelist> | |
359 | <varlistentry> | |
360 | <term>SysV runlevel link farm directory</term> | |
361 | ||
362 | <listitem><para>The location of the SysV runlevel link farm | |
363 | directory varies between distributions. systemd will take the | |
364 | link farm into account when figuring out whether a service | |
365 | shall be enabled. Note that a service unit with a native unit | |
366 | configuration file cannot be started by activating it in the | |
367 | SysV runlevel link farm.</para></listitem> | |
368 | </varlistentry> | |
369 | </variablelist> | |
370 | </refsect1> | |
371 | ||
372 | <refsect1> | |
373 | <title>Signals</title> | |
374 | ||
375 | <variablelist> | |
376 | <varlistentry> | |
377 | <term><constant>SIGTERM</constant></term> | |
378 | ||
379 | <listitem><para>Upon receiving this signal the systemd system | |
380 | manager serializes its state, reexecutes itself and | |
381 | deserializes the saved state again. This is mostly equivalent | |
382 | to <command>systemctl daemon-reexec</command>.</para> | |
383 | ||
384 | <para>systemd user managers will start the | |
385 | <filename>exit.target</filename> unit when this signal is | |
386 | received. This is mostly equivalent to <command>systemctl | |
d60cb656 | 387 | --user start exit.target |
27e64442 | 388 | --job-mode=replace-irreversibly</command>.</para></listitem> |
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389 | </varlistentry> |
390 | ||
391 | <varlistentry> | |
392 | <term><constant>SIGINT</constant></term> | |
393 | ||
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394 | <listitem><para>Upon receiving this signal the systemd system manager will start the |
395 | <filename>ctrl-alt-del.target</filename> unit. This is mostly equivalent to | |
27e64442 | 396 | <command>systemctl start ctrl-alt-del.target --job-mode=replace-irreversibly</command>. If |
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397 | this signal is received more than 7 times per 2s, an immediate reboot is triggered. Note |
398 | that pressing | |
399 | <keycombo><keycap>Ctrl</keycap><keycap>Alt</keycap><keycap>Del</keycap></keycombo> on the | |
400 | console will trigger this signal. Hence, if a reboot is hanging, pressing | |
401 | <keycombo><keycap>Ctrl</keycap><keycap>Alt</keycap><keycap>Del</keycap></keycombo> more than | |
402 | 7 times in 2 seconds is a relatively safe way to trigger an immediate reboot.</para> | |
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403 | |
404 | <para>systemd user managers treat this signal the same way as | |
405 | <constant>SIGTERM</constant>.</para></listitem> | |
406 | </varlistentry> | |
407 | ||
408 | <varlistentry> | |
409 | <term><constant>SIGWINCH</constant></term> | |
410 | ||
411 | <listitem><para>When this signal is received the systemd | |
412 | system manager will start the | |
413 | <filename>kbrequest.target</filename> unit. This is mostly | |
414 | equivalent to <command>systemctl start | |
415 | kbrequest.target</command>.</para> | |
416 | ||
417 | <para>This signal is ignored by systemd user | |
418 | managers.</para></listitem> | |
419 | </varlistentry> | |
420 | ||
421 | <varlistentry> | |
422 | <term><constant>SIGPWR</constant></term> | |
423 | ||
424 | <listitem><para>When this signal is received the systemd | |
425 | manager will start the <filename>sigpwr.target</filename> | |
426 | unit. This is mostly equivalent to <command>systemctl start | |
427 | sigpwr.target</command>.</para></listitem> | |
428 | </varlistentry> | |
429 | ||
430 | <varlistentry> | |
431 | <term><constant>SIGUSR1</constant></term> | |
432 | ||
433 | <listitem><para>When this signal is received the systemd | |
434 | manager will try to reconnect to the D-Bus | |
435 | bus.</para></listitem> | |
436 | </varlistentry> | |
437 | ||
438 | <varlistentry> | |
439 | <term><constant>SIGUSR2</constant></term> | |
440 | ||
441 | <listitem><para>When this signal is received the systemd | |
b938cb90 | 442 | manager will log its complete state in human-readable form. |
798d3a52 ZJS |
443 | The data logged is the same as printed by |
444 | <command>systemd-analyze dump</command>.</para></listitem> | |
445 | </varlistentry> | |
446 | ||
447 | <varlistentry> | |
448 | <term><constant>SIGHUP</constant></term> | |
449 | ||
450 | <listitem><para>Reloads the complete daemon configuration. | |
451 | This is mostly equivalent to <command>systemctl | |
452 | daemon-reload</command>.</para></listitem> | |
453 | </varlistentry> | |
454 | ||
455 | <varlistentry> | |
456 | <term><constant>SIGRTMIN+0</constant></term> | |
457 | ||
458 | <listitem><para>Enters default mode, starts the | |
459 | <filename>default.target</filename> unit. This is mostly | |
d60cb656 | 460 | equivalent to <command>systemctl isolate |
798d3a52 ZJS |
461 | default.target</command>.</para></listitem> |
462 | </varlistentry> | |
463 | ||
464 | <varlistentry> | |
465 | <term><constant>SIGRTMIN+1</constant></term> | |
466 | ||
467 | <listitem><para>Enters rescue mode, starts the | |
468 | <filename>rescue.target</filename> unit. This is mostly | |
469 | equivalent to <command>systemctl isolate | |
470 | rescue.target</command>.</para></listitem> | |
471 | </varlistentry> | |
472 | ||
473 | <varlistentry> | |
474 | <term><constant>SIGRTMIN+2</constant></term> | |
475 | ||
476 | <listitem><para>Enters emergency mode, starts the | |
477 | <filename>emergency.service</filename> unit. This is mostly | |
478 | equivalent to <command>systemctl isolate | |
479 | emergency.service</command>.</para></listitem> | |
480 | </varlistentry> | |
481 | ||
482 | <varlistentry> | |
483 | <term><constant>SIGRTMIN+3</constant></term> | |
484 | ||
485 | <listitem><para>Halts the machine, starts the | |
486 | <filename>halt.target</filename> unit. This is mostly | |
d60cb656 | 487 | equivalent to <command>systemctl start halt.target |
27e64442 | 488 | --job-mode=replace-irreversibly</command>.</para> |
d60cb656 | 489 | </listitem> |
798d3a52 ZJS |
490 | </varlistentry> |
491 | ||
492 | <varlistentry> | |
493 | <term><constant>SIGRTMIN+4</constant></term> | |
494 | ||
495 | <listitem><para>Powers off the machine, starts the | |
496 | <filename>poweroff.target</filename> unit. This is mostly | |
d60cb656 | 497 | equivalent to <command>systemctl start poweroff.target |
27e64442 | 498 | --job-mode=replace-irreversibly</command>.</para> |
d60cb656 | 499 | </listitem> |
798d3a52 ZJS |
500 | </varlistentry> |
501 | ||
502 | <varlistentry> | |
503 | <term><constant>SIGRTMIN+5</constant></term> | |
504 | ||
505 | <listitem><para>Reboots the machine, starts the | |
506 | <filename>reboot.target</filename> unit. This is mostly | |
d60cb656 | 507 | equivalent to <command>systemctl start reboot.target |
27e64442 | 508 | --job-mode=replace-irreversibly</command>.</para> |
d60cb656 | 509 | </listitem> |
798d3a52 ZJS |
510 | </varlistentry> |
511 | ||
512 | <varlistentry> | |
513 | <term><constant>SIGRTMIN+6</constant></term> | |
514 | ||
515 | <listitem><para>Reboots the machine via kexec, starts the | |
516 | <filename>kexec.target</filename> unit. This is mostly | |
d60cb656 | 517 | equivalent to <command>systemctl start kexec.target |
27e64442 | 518 | --job-mode=replace-irreversibly</command>.</para> |
d60cb656 | 519 | </listitem> |
798d3a52 ZJS |
520 | </varlistentry> |
521 | ||
4de66581 LP |
522 | <varlistentry> |
523 | <term><constant>SIGRTMIN+7</constant></term> | |
524 | ||
525 | <listitem><para>Reboots userspace, starts the <filename>soft-reboot.target</filename> unit. This is | |
526 | mostly equivalent to <command>systemctl start soft-reboot.target | |
527 | --job-mode=replace-irreversibly</command>.</para> | |
ec07c3c8 AK |
528 | |
529 | <xi:include href="version-info.xml" xpointer="v254"/> | |
4de66581 LP |
530 | </listitem> |
531 | </varlistentry> | |
532 | ||
798d3a52 ZJS |
533 | <varlistentry> |
534 | <term><constant>SIGRTMIN+13</constant></term> | |
535 | ||
536 | <listitem><para>Immediately halts the machine.</para></listitem> | |
537 | </varlistentry> | |
538 | ||
539 | <varlistentry> | |
540 | <term><constant>SIGRTMIN+14</constant></term> | |
541 | ||
542 | <listitem><para>Immediately powers off the machine.</para></listitem> | |
543 | </varlistentry> | |
544 | ||
545 | <varlistentry> | |
546 | <term><constant>SIGRTMIN+15</constant></term> | |
547 | ||
548 | <listitem><para>Immediately reboots the machine.</para></listitem> | |
549 | </varlistentry> | |
550 | ||
551 | <varlistentry> | |
552 | <term><constant>SIGRTMIN+16</constant></term> | |
553 | ||
554 | <listitem><para>Immediately reboots the machine with kexec.</para></listitem> | |
555 | </varlistentry> | |
556 | ||
4de66581 LP |
557 | <varlistentry> |
558 | <term><constant>SIGRTMIN+17</constant></term> | |
559 | ||
ec07c3c8 AK |
560 | <listitem><para>Immediately reboots the userspace.</para> |
561 | ||
562 | <xi:include href="version-info.xml" xpointer="v254"/></listitem> | |
4de66581 LP |
563 | </varlistentry> |
564 | ||
798d3a52 ZJS |
565 | <varlistentry> |
566 | <term><constant>SIGRTMIN+20</constant></term> | |
567 | ||
568 | <listitem><para>Enables display of status messages on the | |
569 | console, as controlled via | |
570 | <varname>systemd.show_status=1</varname> on the kernel command | |
571 | line.</para></listitem> | |
572 | </varlistentry> | |
573 | ||
574 | <varlistentry> | |
575 | <term><constant>SIGRTMIN+21</constant></term> | |
576 | ||
577 | <listitem><para>Disables display of | |
578 | status messages on the console, as | |
579 | controlled via | |
580 | <varname>systemd.show_status=0</varname> | |
581 | on the kernel command | |
582 | line.</para></listitem> | |
583 | </varlistentry> | |
584 | ||
585 | <varlistentry> | |
586 | <term><constant>SIGRTMIN+22</constant></term> | |
a6ecbf83 FB |
587 | |
588 | <listitem><para>Sets the service manager's log level to <literal>debug</literal>, in a fashion equivalent to | |
589 | <varname>systemd.log_level=debug</varname> on the kernel command line.</para></listitem> | |
590 | </varlistentry> | |
591 | ||
592 | <varlistentry> | |
798d3a52 ZJS |
593 | <term><constant>SIGRTMIN+23</constant></term> |
594 | ||
a6ecbf83 FB |
595 | <listitem><para>Restores the log level to its configured value. The configured value is derived from – in order |
596 | of priority – the value specified with <varname>systemd.log-level=</varname> on the kernel command line, or the | |
597 | value specified with <option>LogLevel=</option> in the configuration file, or the built-in default of | |
ec07c3c8 AK |
598 | <literal>info</literal>.</para> |
599 | ||
600 | <xi:include href="version-info.xml" xpointer="v239"/></listitem> | |
798d3a52 ZJS |
601 | </varlistentry> |
602 | ||
603 | <varlistentry> | |
604 | <term><constant>SIGRTMIN+24</constant></term> | |
605 | ||
606 | <listitem><para>Immediately exits the manager (only available | |
ec07c3c8 AK |
607 | for --user instances).</para> |
608 | ||
609 | <xi:include href="version-info.xml" xpointer="v195"/></listitem> | |
798d3a52 ZJS |
610 | </varlistentry> |
611 | ||
463aef23 FB |
612 | <varlistentry> |
613 | <term><constant>SIGRTMIN+25</constant></term> | |
614 | ||
615 | <listitem><para>Upon receiving this signal the systemd manager will reexecute itself. This | |
616 | is mostly equivalent to <command>systemctl daemon-reexec</command> except that it will be | |
617 | done asynchronously.</para> | |
618 | ||
619 | <para>The systemd system manager treats this signal the same way as | |
ec07c3c8 AK |
620 | <constant>SIGTERM</constant>.</para> |
621 | ||
622 | <xi:include href="version-info.xml" xpointer="v250"/></listitem> | |
463aef23 FB |
623 | </varlistentry> |
624 | ||
798d3a52 ZJS |
625 | <varlistentry> |
626 | <term><constant>SIGRTMIN+26</constant></term> | |
bda7d78b FB |
627 | |
628 | <listitem><para>Restores the log target to its configured value. The configured value is derived from – in | |
629 | order of priority – the value specified with <varname>systemd.log-target=</varname> on the kernel command line, | |
630 | or the value specified with <option>LogTarget=</option> in the configuration file, or the built-in | |
ec07c3c8 AK |
631 | default.</para> |
632 | ||
633 | <xi:include href="version-info.xml" xpointer="v239"/></listitem> | |
bda7d78b FB |
634 | </varlistentry> |
635 | ||
636 | <varlistentry> | |
798d3a52 ZJS |
637 | <term><constant>SIGRTMIN+27</constant></term> |
638 | <term><constant>SIGRTMIN+28</constant></term> | |
639 | ||
bda7d78b FB |
640 | <listitem><para>Sets the log target to <literal>console</literal> on <constant>SIGRTMIN+27</constant> (or |
641 | <literal>kmsg</literal> on <constant>SIGRTMIN+28</constant>), in a fashion equivalent to | |
642 | <varname>systemd.log_target=console</varname> (or <varname>systemd.log_target=kmsg</varname> on | |
aefdc112 AK |
643 | <constant>SIGRTMIN+28</constant>) on the kernel command line.</para> |
644 | ||
645 | <xi:include href="version-info.xml" xpointer="v239"/></listitem> | |
798d3a52 ZJS |
646 | </varlistentry> |
647 | </variablelist> | |
648 | </refsect1> | |
649 | ||
650 | <refsect1> | |
651 | <title>Environment</title> | |
652 | ||
d5158643 | 653 | <para>The environment block for the system manager is initially set by the kernel. (In particular, |
f2f40edc | 654 | <literal>key=value</literal> assignments on the kernel command line are turned into environment |
d5158643 ZJS |
655 | variables for PID 1). For the user manager, the system manager sets the environment as described in the |
656 | "Environment Variables in Spawned Processes" section of | |
657 | <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>. The | |
658 | <varname>DefaultEnvironment=</varname> setting in the system manager applies to all services including | |
659 | <filename>user@.service</filename>. Additional entries may be configured (as for any other service) | |
660 | through the <varname>Environment=</varname> and <varname>EnvironmentFile=</varname> settings for | |
661 | <filename>user@.service</filename> (see | |
662 | <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>). Also, | |
663 | additional environment variables may be set through the <varname>ManagerEnvironment=</varname> setting in | |
664 | <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry> | |
665 | and | |
666 | <citerefentry><refentrytitle>systemd-user.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>. | |
667 | </para> | |
668 | ||
669 | <para>Some of the variables understood by <command>systemd</command>:</para> | |
670 | ||
798d3a52 | 671 | <variablelist class='environment-variables'> |
798d3a52 | 672 | <varlistentry> |
b4c87f7d ZJS |
673 | <term><varname>$SYSTEMD_LOG_LEVEL</varname></term> |
674 | <listitem><xi:include href="common-variables.xml" xpointer="log-level-body" /> | |
675 | ||
676 | <para>This can be overridden with <option>--log-level=</option>.</para></listitem> | |
798d3a52 ZJS |
677 | </varlistentry> |
678 | ||
798d3a52 | 679 | <varlistentry> |
b4c87f7d ZJS |
680 | <term><varname>$SYSTEMD_LOG_COLOR</varname></term> |
681 | <listitem><xi:include href="common-variables.xml" xpointer="log-color-body" /> | |
682 | ||
683 | <para>This can be overridden with <option>--log-color=</option>.</para></listitem> | |
798d3a52 ZJS |
684 | </varlistentry> |
685 | ||
798d3a52 | 686 | <varlistentry> |
b4c87f7d ZJS |
687 | <term><varname>$SYSTEMD_LOG_TIME</varname></term> |
688 | <listitem><xi:include href="common-variables.xml" xpointer="log-time-body" /> | |
689 | ||
ec07c3c8 AK |
690 | <para>This can be overridden with <option>--log-time=</option>.</para> |
691 | ||
692 | <xi:include href="version-info.xml" xpointer="v246"/></listitem> | |
798d3a52 ZJS |
693 | </varlistentry> |
694 | ||
798d3a52 | 695 | <varlistentry> |
b4c87f7d ZJS |
696 | <term><varname>$SYSTEMD_LOG_LOCATION</varname></term> |
697 | <listitem><xi:include href="common-variables.xml" xpointer="log-location-body" /> | |
698 | ||
699 | <para>This can be overridden with <option>--log-location=</option>.</para></listitem> | |
798d3a52 ZJS |
700 | </varlistentry> |
701 | ||
702 | <varlistentry> | |
b4c87f7d | 703 | <term><varname>$SYSTEMD_LOG_TID</varname></term> |
ec07c3c8 AK |
704 | <listitem><xi:include href="common-variables.xml" xpointer="log-tid-body" /> |
705 | ||
706 | <xi:include href="version-info.xml" xpointer="v247"/></listitem> | |
9ee806d1 LP |
707 | </varlistentry> |
708 | ||
709 | <varlistentry> | |
b4c87f7d ZJS |
710 | <term><varname>$SYSTEMD_LOG_TARGET</varname></term> |
711 | <listitem><xi:include href="common-variables.xml" xpointer="log-target-body" /> | |
712 | ||
713 | <para>This can be overridden with <option>--log-target=</option>.</para></listitem> | |
798d3a52 ZJS |
714 | </varlistentry> |
715 | ||
8750a06b DDM |
716 | <varlistentry> |
717 | <term><varname>$SYSTEMD_LOG_RATELIMIT_KMSG</varname></term> | |
ec07c3c8 AK |
718 | <listitem><xi:include href="common-variables.xml" xpointer="log-ratelimit-kmsg-body" /> |
719 | ||
720 | <xi:include href="version-info.xml" xpointer="v254"/></listitem> | |
8750a06b DDM |
721 | </varlistentry> |
722 | ||
798d3a52 ZJS |
723 | <varlistentry> |
724 | <term><varname>$XDG_CONFIG_HOME</varname></term> | |
725 | <term><varname>$XDG_CONFIG_DIRS</varname></term> | |
726 | <term><varname>$XDG_DATA_HOME</varname></term> | |
727 | <term><varname>$XDG_DATA_DIRS</varname></term> | |
728 | ||
729 | <listitem><para>The systemd user manager uses these variables | |
730 | in accordance to the <ulink | |
41d6f3bf | 731 | url="https://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html">XDG |
798d3a52 ZJS |
732 | Base Directory specification</ulink> to find its |
733 | configuration.</para></listitem> | |
734 | </varlistentry> | |
735 | ||
736 | <varlistentry> | |
737 | <term><varname>$SYSTEMD_UNIT_PATH</varname></term> | |
5b058473 BB |
738 | <term><varname>$SYSTEMD_GENERATOR_PATH</varname></term> |
739 | <term><varname>$SYSTEMD_ENVIRONMENT_GENERATOR_PATH</varname></term> | |
740 | ||
741 | <listitem><para>Controls where systemd looks for unit files and | |
742 | generators.</para> | |
743 | <para>These variables may contain a list of paths, separated by colons | |
744 | (<literal>:</literal>). When set, if the list ends with an empty | |
745 | component (<literal>...:</literal>), this list is prepended to the | |
885a4e6c | 746 | usual set of paths. Otherwise, the specified list replaces the usual |
5b058473 BB |
747 | set of paths. |
748 | </para></listitem> | |
798d3a52 ZJS |
749 | </varlistentry> |
750 | ||
4ef3ca34 ZJS |
751 | <xi:include href="common-variables.xml" xpointer="pager"/> |
752 | <xi:include href="common-variables.xml" xpointer="less"/> | |
753 | <xi:include href="common-variables.xml" xpointer="lesscharset"/> | |
754 | <xi:include href="common-variables.xml" xpointer="lesssecure"/> | |
755 | <xi:include href="common-variables.xml" xpointer="colors"/> | |
756 | <xi:include href="common-variables.xml" xpointer="urlify"/> | |
23b27b39 | 757 | |
798d3a52 ZJS |
758 | <varlistentry> |
759 | <term><varname>$LISTEN_PID</varname></term> | |
760 | <term><varname>$LISTEN_FDS</varname></term> | |
8dd4c05b | 761 | <term><varname>$LISTEN_FDNAMES</varname></term> |
798d3a52 ZJS |
762 | |
763 | <listitem><para>Set by systemd for supervised processes during | |
764 | socket-based activation. See | |
765 | <citerefentry><refentrytitle>sd_listen_fds</refentrytitle><manvolnum>3</manvolnum></citerefentry> | |
acf553b0 | 766 | for more information.</para></listitem> |
798d3a52 ZJS |
767 | </varlistentry> |
768 | ||
769 | <varlistentry> | |
770 | <term><varname>$NOTIFY_SOCKET</varname></term> | |
771 | ||
772 | <listitem><para>Set by systemd for supervised processes for | |
773 | status and start-up completion notification. See | |
774 | <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry> | |
acf553b0 | 775 | for more information.</para></listitem> |
798d3a52 ZJS |
776 | </varlistentry> |
777 | </variablelist> | |
8ce202fa LP |
778 | |
779 | <para>For further environment variables understood by systemd and its various components, see <ulink | |
780 | url="https://systemd.io/ENVIRONMENT">Known Environment Variables</ulink>.</para> | |
798d3a52 ZJS |
781 | </refsect1> |
782 | ||
783 | <refsect1> | |
784 | <title>Kernel Command Line</title> | |
785 | ||
ef2c966a DDM |
786 | <para>When run as the system instance, systemd parses a number of options listed below. They can be |
787 | specified as kernel command line arguments which are parsed from a number of sources depending on the | |
788 | environment in which systemd is executed. If run inside a Linux container, these options are parsed from | |
789 | the command line arguments passed to systemd itself, next to any of the command line options listed in | |
790 | the Options section above. If run outside of Linux containers, these arguments are parsed from | |
791 | <filename>/proc/cmdline</filename> and from the <literal>SystemdOptions</literal> EFI variable | |
7e90814f ZJS |
792 | (on EFI systems) instead. Options from <filename>/proc/cmdline</filename> have higher priority.</para> |
793 | ||
794 | <para>Note: use of <literal>SystemdOptions</literal> is deprecated.</para> | |
795 | ||
796 | <para>The following variables are understood:</para> | |
798d3a52 ZJS |
797 | |
798 | <variablelist class='kernel-commandline-options'> | |
799 | <varlistentry> | |
800 | <term><varname>systemd.unit=</varname></term> | |
801 | <term><varname>rd.systemd.unit=</varname></term> | |
802 | ||
55c041b4 LP |
803 | <listitem><para>Overrides the unit to activate on boot. Defaults to |
804 | <filename>default.target</filename>. This may be used to temporarily boot into a different boot unit, | |
805 | for example <filename>rescue.target</filename> or <filename>emergency.service</filename>. See | |
798d3a52 | 806 | <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry> |
55c041b4 LP |
807 | for details about these units. The option prefixed with <literal>rd.</literal> is honored only in the |
808 | initrd, while the one that is not prefixed only in the main system.</para></listitem> | |
798d3a52 ZJS |
809 | </varlistentry> |
810 | ||
811 | <varlistentry> | |
770c4777 | 812 | <term><varname>systemd.dump_core</varname></term> |
798d3a52 | 813 | |
770c4777 ZJS |
814 | <listitem><para>Takes a boolean argument or enables the option if specified |
815 | without an argument. If enabled, the systemd manager (PID 1) dumps core when | |
816 | it crashes. Otherwise, no core dump is created. Defaults to enabled.</para> | |
ec07c3c8 AK |
817 | |
818 | <xi:include href="version-info.xml" xpointer="v233"/> | |
770c4777 | 819 | </listitem> |
b9e74c39 LP |
820 | </varlistentry> |
821 | ||
822 | <varlistentry> | |
770c4777 | 823 | <term><varname>systemd.crash_chvt</varname></term> |
b9e74c39 | 824 | |
e9dd6984 ZJS |
825 | <listitem><para>Takes a positive integer, or a boolean argument. Can be also specified without an |
826 | argument, with the same effect as a positive boolean. If a positive integer (in the range 1–63) is | |
827 | specified, the system manager (PID 1) will activate the specified virtual terminal when it crashes. | |
828 | Defaults to disabled, meaning that no such switch is attempted. If set to enabled, the virtual | |
ec07c3c8 AK |
829 | terminal the kernel messages are written to is used instead.</para> |
830 | ||
831 | <xi:include href="version-info.xml" xpointer="v233"/></listitem> | |
798d3a52 ZJS |
832 | </varlistentry> |
833 | ||
834 | <varlistentry> | |
770c4777 | 835 | <term><varname>systemd.crash_shell</varname></term> |
798d3a52 | 836 | |
770c4777 ZJS |
837 | <listitem><para>Takes a boolean argument or enables the option if specified |
838 | without an argument. If enabled, the system manager (PID 1) spawns a shell | |
839 | when it crashes, after a 10s delay. Otherwise, no shell is spawned. Defaults | |
840 | to disabled, for security reasons, as the shell is not protected by password | |
ec07c3c8 AK |
841 | authentication.</para> |
842 | ||
843 | <xi:include href="version-info.xml" xpointer="v233"/></listitem> | |
798d3a52 ZJS |
844 | </varlistentry> |
845 | ||
846 | <varlistentry> | |
770c4777 | 847 | <term><varname>systemd.crash_reboot</varname></term> |
798d3a52 | 848 | |
770c4777 ZJS |
849 | <listitem><para>Takes a boolean argument or enables the option if specified |
850 | without an argument. If enabled, the system manager (PID 1) will reboot the | |
851 | machine automatically when it crashes, after a 10s delay. Otherwise, the | |
852 | system will hang indefinitely. Defaults to disabled, in order to avoid a | |
853 | reboot loop. If combined with <varname>systemd.crash_shell</varname>, the | |
ec07c3c8 AK |
854 | system is rebooted after the shell exits.</para> |
855 | ||
aefdc112 | 856 | <xi:include href="version-info.xml" xpointer="v227"/></listitem> |
798d3a52 ZJS |
857 | </varlistentry> |
858 | ||
859 | <varlistentry> | |
770c4777 | 860 | <term><varname>systemd.confirm_spawn</varname></term> |
798d3a52 | 861 | |
770c4777 ZJS |
862 | <listitem><para>Takes a boolean argument or a path to the virtual console |
863 | where the confirmation messages should be emitted. Can be also specified | |
864 | without an argument, with the same effect as a positive boolean. If enabled, | |
865 | the system manager (PID 1) asks for confirmation when spawning processes | |
866 | using <option>/dev/console</option>. If a path or a console name (such as | |
867 | <literal>ttyS0</literal>) is provided, the virtual console pointed to by this | |
868 | path or described by the give name will be used instead. Defaults to disabled. | |
ec07c3c8 AK |
869 | </para> |
870 | ||
871 | <xi:include href="version-info.xml" xpointer="v233"/></listitem> | |
798d3a52 ZJS |
872 | </varlistentry> |
873 | ||
2a12e32e JK |
874 | <varlistentry> |
875 | <term><varname>systemd.service_watchdogs=</varname></term> | |
876 | ||
877 | <listitem><para>Takes a boolean argument. If disabled, all service runtime | |
878 | watchdogs (<option>WatchdogSec=</option>) and emergency actions (e.g. | |
879 | <option>OnFailure=</option> or <option>StartLimitAction=</option>) are | |
880 | ignored by the system manager (PID 1); see | |
881 | <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>. | |
882 | Defaults to enabled, i.e. watchdogs and failure actions are processed | |
883 | normally. The hardware watchdog is not affected by this | |
ec07c3c8 AK |
884 | option.</para> |
885 | ||
886 | <xi:include href="version-info.xml" xpointer="v237"/></listitem> | |
2a12e32e JK |
887 | </varlistentry> |
888 | ||
798d3a52 | 889 | <varlistentry> |
770c4777 | 890 | <term><varname>systemd.show_status</varname></term> |
798d3a52 | 891 | |
0d066dd1 ZJS |
892 | <listitem><para>Takes a boolean argument or the constants <constant>error</constant> and |
893 | <constant>auto</constant>. Can be also specified without an argument, with the same effect as a | |
894 | positive boolean. If enabled, the systemd manager (PID 1) shows terse service status updates on the | |
895 | console during bootup. With <constant>error</constant>, only messages about failures are shown, but | |
896 | boot is otherwise quiet. <constant>auto</constant> behaves like <option>false</option> until there is | |
897 | a significant delay in boot. Defaults to enabled, unless <option>quiet</option> is passed as kernel | |
898 | command line option, in which case it defaults to <constant>error</constant>. If specified overrides | |
899 | the system manager configuration file option <option>ShowStatus=</option>, see | |
770c4777 | 900 | <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>. |
ec07c3c8 AK |
901 | </para> |
902 | ||
903 | <xi:include href="version-info.xml" xpointer="v233"/></listitem> | |
798d3a52 ZJS |
904 | </varlistentry> |
905 | ||
36cf4507 ZJS |
906 | <varlistentry> |
907 | <term><varname>systemd.status_unit_format=</varname></term> | |
908 | ||
580e198a PM |
909 | <listitem><para>Takes <option>name</option>, <option>description</option> or |
910 | <option>combined</option> as the value. If <option>name</option>, the system manager will use unit | |
911 | names in status messages. If <option>combined</option>, the system manager will use unit names and | |
912 | description in status messages. When specified, overrides the system manager configuration file | |
913 | option <option>StatusUnitFormat=</option>, see | |
36cf4507 | 914 | <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>. |
ec07c3c8 AK |
915 | </para> |
916 | ||
917 | <xi:include href="version-info.xml" xpointer="v243"/></listitem> | |
36cf4507 ZJS |
918 | </varlistentry> |
919 | ||
798d3a52 | 920 | <varlistentry> |
770c4777 | 921 | <term><varname>systemd.log_color</varname></term> |
798d3a52 | 922 | <term><varname>systemd.log_level=</varname></term> |
2526af6d | 923 | <term><varname>systemd.log_location</varname></term> |
3d5f0138 | 924 | <term><varname>systemd.log_target=</varname></term> |
c5673ed0 | 925 | <term><varname>systemd.log_time</varname></term> |
9ee806d1 | 926 | <term><varname>systemd.log_tid</varname></term> |
8750a06b | 927 | <term><varname>systemd.log_ratelimit_kmsg</varname></term> |
798d3a52 | 928 | |
770c4777 | 929 | <listitem><para>Controls log output, with the same effect as the |
9ee806d1 LP |
930 | <varname>$SYSTEMD_LOG_COLOR</varname>, <varname>$SYSTEMD_LOG_LEVEL</varname>, |
931 | <varname>$SYSTEMD_LOG_LOCATION</varname>, <varname>$SYSTEMD_LOG_TARGET</varname>, | |
8750a06b DDM |
932 | <varname>$SYSTEMD_LOG_TIME</varname>, <varname>$SYSTEMD_LOG_TID</varname> and |
933 | <varname>$SYSTEMD_LOG_RATELIMIT_KMSG</varname> environment variables described above. | |
934 | <varname>systemd.log_color</varname>, <varname>systemd.log_location</varname>, | |
935 | <varname>systemd.log_time</varname>, <varname>systemd.log_tid</varname> and | |
936 | <varname>systemd.log_ratelimit_kmsg</varname> can be specified without | |
9ee806d1 | 937 | an argument, with the same effect as a positive boolean.</para></listitem> |
798d3a52 ZJS |
938 | </varlistentry> |
939 | ||
940 | <varlistentry> | |
941 | <term><varname>systemd.default_standard_output=</varname></term> | |
942 | <term><varname>systemd.default_standard_error=</varname></term> | |
c035f376 ZJS |
943 | |
944 | <listitem><para>Controls default standard output and error output for services and sockets. That is, | |
945 | controls the default for <option>StandardOutput=</option> and <option>StandardError=</option> (see | |
946 | <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry> for | |
947 | details). Takes one of <option>inherit</option>, <option>null</option>, <option>tty</option>, | |
948 | <option>journal</option>, <option>journal+console</option>, <option>kmsg</option>, | |
949 | <option>kmsg+console</option>. If the argument is omitted | |
950 | <varname>systemd.default-standard-output=</varname> defaults to <option>journal</option> and | |
951 | <varname>systemd.default-standard-error=</varname> to <option>inherit</option>.</para></listitem> | |
798d3a52 ZJS |
952 | </varlistentry> |
953 | ||
954 | <varlistentry> | |
955 | <term><varname>systemd.setenv=</varname></term> | |
956 | ||
957 | <listitem><para>Takes a string argument in the form | |
958 | VARIABLE=VALUE. May be used to set default environment | |
959 | variables to add to forked child processes. May be used more | |
960 | than once to set multiple variables.</para></listitem> | |
961 | </varlistentry> | |
962 | ||
ee48dbd5 NC |
963 | <varlistentry> |
964 | <term><varname>systemd.machine_id=</varname></term> | |
965 | ||
966 | <listitem><para>Takes a 32 character hex value to be | |
967 | used for setting the machine-id. Intended mostly for | |
968 | network booting where the same machine-id is desired | |
ec07c3c8 AK |
969 | for every boot.</para> |
970 | ||
971 | <xi:include href="version-info.xml" xpointer="v229"/></listitem> | |
ee48dbd5 NC |
972 | </varlistentry> |
973 | ||
72267a55 LP |
974 | <varlistentry> |
975 | <term><varname>systemd.set_credential=</varname></term> | |
de70ecb3 | 976 | <term><varname>systemd.set_credential_binary=</varname></term> |
72267a55 LP |
977 | |
978 | <listitem><para>Sets a system credential, which can then be propagated to system services using the | |
bbfb25f4 | 979 | <varname>ImportCredential=</varname> or <varname>LoadCredential=</varname> setting, see |
72267a55 | 980 | <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry> for |
de70ecb3 LP |
981 | details. Takes a pair of credential name and value, separated by a colon. The |
982 | <varname>systemd.set_credential=</varname> parameter expects the credential value in literal text | |
983 | form, the <varname>systemd.set_credential_binary=</varname> parameter takes binary data encoded in | |
984 | Base64. Note that the kernel command line is typically accessible by unprivileged programs in | |
72267a55 LP |
985 | <filename>/proc/cmdline</filename>. Thus, this mechanism is not suitable for transferring sensitive |
986 | data. Use it only for data that is not sensitive (e.g. public keys/certificates, rather than private | |
fe672fe5 LP |
987 | keys), or in testing/debugging environments.</para> |
988 | ||
989 | <para>For further information see <ulink url="https://systemd.io/CREDENTIALS">System and Service | |
aefdc112 AK |
990 | Credentials</ulink> documentation.</para> |
991 | ||
992 | <xi:include href="version-info.xml" xpointer="v251"/></listitem> | |
72267a55 LP |
993 | </varlistentry> |
994 | ||
995 | <varlistentry> | |
996 | <term><varname>systemd.import_credentials=</varname></term> | |
997 | ||
998 | <listitem><para>Takes a boolean argument. If false disables importing credentials from the kernel | |
8de7de46 | 999 | command line, the DMI/SMBIOS OEM string table, the qemu_fw_cfg subsystem or the EFI kernel |
ec07c3c8 AK |
1000 | stub.</para> |
1001 | ||
1002 | <xi:include href="version-info.xml" xpointer="v251"/></listitem> | |
72267a55 LP |
1003 | </varlistentry> |
1004 | ||
798d3a52 ZJS |
1005 | <varlistentry> |
1006 | <term><varname>quiet</varname></term> | |
1007 | ||
1008 | <listitem><para>Turn off status output at boot, much like | |
964c4eda | 1009 | <varname>systemd.show_status=no</varname> would. Note that |
798d3a52 ZJS |
1010 | this option is also read by the kernel itself and disables |
1011 | kernel log output. Passing this option hence turns off the | |
1012 | usual output from both the system manager and the kernel. | |
ec07c3c8 AK |
1013 | </para> |
1014 | ||
1015 | <xi:include href="version-info.xml" xpointer="v186"/></listitem> | |
798d3a52 ZJS |
1016 | </varlistentry> |
1017 | ||
1018 | <varlistentry> | |
1019 | <term><varname>debug</varname></term> | |
1020 | ||
1021 | <listitem><para>Turn on debugging output. This is equivalent | |
1022 | to <varname>systemd.log_level=debug</varname>. Note that this | |
1023 | option is also read by the kernel itself and enables kernel | |
1024 | debug output. Passing this option hence turns on the debug | |
1025 | output from both the system manager and the | |
ec07c3c8 AK |
1026 | kernel.</para> |
1027 | ||
1028 | <xi:include href="version-info.xml" xpointer="v205"/></listitem> | |
798d3a52 ZJS |
1029 | </varlistentry> |
1030 | ||
1031 | <varlistentry> | |
1032 | <term><varname>emergency</varname></term> | |
dcd61450 | 1033 | <term><varname>rd.emergency</varname></term> |
798d3a52 ZJS |
1034 | <term><varname>-b</varname></term> |
1035 | ||
1036 | <listitem><para>Boot into emergency mode. This is equivalent | |
dcd61450 IS |
1037 | to <varname>systemd.unit=emergency.target</varname> or |
1038 | <varname>rd.systemd.unit=emergency.target</varname>, respectively, and | |
aefdc112 AK |
1039 | provided for compatibility reasons and to be easier to type.</para> |
1040 | ||
1041 | <xi:include href="version-info.xml" xpointer="v186"/></listitem> | |
798d3a52 ZJS |
1042 | </varlistentry> |
1043 | ||
1044 | <varlistentry> | |
1045 | <term><varname>rescue</varname></term> | |
dcd61450 | 1046 | <term><varname>rd.rescue</varname></term> |
798d3a52 ZJS |
1047 | <term><varname>single</varname></term> |
1048 | <term><varname>s</varname></term> | |
1049 | <term><varname>S</varname></term> | |
1050 | <term><varname>1</varname></term> | |
1051 | ||
1052 | <listitem><para>Boot into rescue mode. This is equivalent to | |
dcd61450 IS |
1053 | <varname>systemd.unit=rescue.target</varname> or |
1054 | <varname>rd.systemd.unit=rescue.target</varname>, respectively, and | |
aefdc112 AK |
1055 | provided for compatibility reasons and to be easier to type.</para> |
1056 | ||
1057 | <xi:include href="version-info.xml" xpointer="v186"/></listitem> | |
798d3a52 ZJS |
1058 | </varlistentry> |
1059 | ||
1060 | <varlistentry> | |
1061 | <term><varname>2</varname></term> | |
1062 | <term><varname>3</varname></term> | |
1063 | <term><varname>4</varname></term> | |
1064 | <term><varname>5</varname></term> | |
1065 | ||
1066 | <listitem><para>Boot into the specified legacy SysV runlevel. | |
1067 | These are equivalent to | |
1068 | <varname>systemd.unit=runlevel2.target</varname>, | |
1069 | <varname>systemd.unit=runlevel3.target</varname>, | |
1070 | <varname>systemd.unit=runlevel4.target</varname>, and | |
1071 | <varname>systemd.unit=runlevel5.target</varname>, | |
1072 | respectively, and provided for compatibility reasons and to be | |
ec07c3c8 AK |
1073 | easier to type.</para> |
1074 | ||
1075 | <xi:include href="version-info.xml" xpointer="v186"/></listitem> | |
798d3a52 ZJS |
1076 | </varlistentry> |
1077 | ||
1078 | <varlistentry> | |
1079 | <term><varname>locale.LANG=</varname></term> | |
1080 | <term><varname>locale.LANGUAGE=</varname></term> | |
1081 | <term><varname>locale.LC_CTYPE=</varname></term> | |
1082 | <term><varname>locale.LC_NUMERIC=</varname></term> | |
1083 | <term><varname>locale.LC_TIME=</varname></term> | |
1084 | <term><varname>locale.LC_COLLATE=</varname></term> | |
1085 | <term><varname>locale.LC_MONETARY=</varname></term> | |
1086 | <term><varname>locale.LC_MESSAGES=</varname></term> | |
1087 | <term><varname>locale.LC_PAPER=</varname></term> | |
1088 | <term><varname>locale.LC_NAME=</varname></term> | |
1089 | <term><varname>locale.LC_ADDRESS=</varname></term> | |
1090 | <term><varname>locale.LC_TELEPHONE=</varname></term> | |
1091 | <term><varname>locale.LC_MEASUREMENT=</varname></term> | |
1092 | <term><varname>locale.LC_IDENTIFICATION=</varname></term> | |
1093 | ||
1094 | <listitem><para>Set the system locale to use. This overrides | |
1095 | the settings in <filename>/etc/locale.conf</filename>. For | |
b938cb90 | 1096 | more information, see |
3ba3a79d | 1097 | <citerefentry project='man-pages'><refentrytitle>locale.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry> |
798d3a52 | 1098 | and |
3ba3a79d | 1099 | <citerefentry project='man-pages'><refentrytitle>locale</refentrytitle><manvolnum>7</manvolnum></citerefentry>. |
ec07c3c8 AK |
1100 | </para> |
1101 | ||
1102 | <xi:include href="version-info.xml" xpointer="v186"/></listitem> | |
798d3a52 ZJS |
1103 | </varlistentry> |
1104 | </variablelist> | |
1105 | ||
1106 | <para>For other kernel command line parameters understood by | |
1107 | components of the core OS, please refer to | |
1108 | <citerefentry><refentrytitle>kernel-command-line</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para> | |
1109 | </refsect1> | |
c035f376 | 1110 | |
452cfd98 LP |
1111 | <refsect1> |
1112 | <title>System credentials</title> | |
1113 | ||
49850c1e LP |
1114 | <para>During initialization the service manager will import credentials from various sources into the |
1115 | system's set of credentials, which can then be propagated into services and consumed by | |
1116 | generators:</para> | |
1117 | ||
1118 | <itemizedlist> | |
1119 | <listitem><para>When the service manager first initializes it will read system credentials from SMBIOS | |
1120 | Type 11 vendor strings | |
1121 | <varname>io.systemd.credential:<replaceable>name</replaceable>=<replaceable>value</replaceable></varname>, | |
1122 | and | |
1123 | <varname>io.systemd.credential.binary:<replaceable>name</replaceable>=<replaceable>value</replaceable></varname>.</para></listitem> | |
1124 | ||
1125 | <listitem><para>At the same time it will import credentials from QEMU <literal>fw_cfg</literal>. (Note | |
1126 | that the SMBIOS mechanism is generally preferred, because it is faster and generic.)</para></listitem> | |
1127 | ||
1128 | <listitem><para>Credentials may be passed via the kernel command line, using the | |
1129 | <varname>systemd.set-credential=</varname> parameter, see above.</para></listitem> | |
1130 | ||
1131 | <listitem><para>Credentials may be passed from the UEFI environment via | |
1132 | <citerefentry><refentrytitle>systemd-stub</refentrytitle><manvolnum>7</manvolnum></citerefentry>.</para></listitem> | |
1133 | ||
1134 | <listitem><para>When the service manager is invoked during the initrd → host transition it will import | |
1135 | all files in <filename>/run/credentials/@initrd/</filename> as system credentials.</para></listitem> | |
1136 | </itemizedlist> | |
1137 | ||
1138 | <para>Invoke | |
1139 | <citerefentry><refentrytitle>systemd-creds</refentrytitle><manvolnum>1</manvolnum></citerefentry> as | |
1140 | follows to see the list of credentials passed into the system:</para> | |
1141 | ||
1142 | <programlisting># systemd-creds --system list</programlisting> | |
1143 | ||
1144 | <para>For further information see <ulink url="https://systemd.io/CREDENTIALS">System and Service | |
1145 | Credentials</ulink> documentation.</para> | |
1146 | ||
1147 | <para>The service manager when run as PID 1 consumes the following system credentials:</para> | |
452cfd98 | 1148 | |
8914f7e8 | 1149 | <variablelist class='system-credentials'> |
452cfd98 LP |
1150 | <varlistentry> |
1151 | <term><varname>vmm.notify_socket</varname></term> | |
1152 | <listitem> | |
1153 | <para>Contains a <constant>AF_VSOCK</constant> or <constant>AF_UNIX</constant> address where to | |
1154 | send a <constant>READY=1</constant> notification datagram when the system has finished booting. See | |
1155 | <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry> for | |
1156 | more information. Note that in case the hypervisor does not support <constant>SOCK_DGRAM</constant> | |
1157 | over <constant>AF_VSOCK</constant>, <constant>SOCK_SEQPACKET</constant> will be tried instead. The | |
1158 | credential payload for <constant>AF_VSOCK</constant> should be in the form | |
1159 | <literal>vsock:CID:PORT</literal>.</para> | |
1160 | ||
1161 | <para>This feature is useful for hypervisors/VMMs or other processes on the host to receive a | |
1162 | notification via VSOCK when a virtual machine has finished booting.</para> | |
ec07c3c8 AK |
1163 | |
1164 | <xi:include href="version-info.xml" xpointer="v254"/> | |
452cfd98 LP |
1165 | </listitem> |
1166 | </varlistentry> | |
deb0d489 LP |
1167 | |
1168 | <varlistentry> | |
1169 | <term><varname>system.machine_id</varname></term> | |
1170 | <listitem> | |
1171 | <para>Takes a 128bit hexadecimal ID to initialize <filename>/etc/machine-id</filename> from, if the | |
1172 | file is not set up yet. See | |
1173 | <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry> for | |
1174 | details.</para> | |
ec07c3c8 AK |
1175 | |
1176 | <xi:include href="version-info.xml" xpointer="v254"/> | |
deb0d489 LP |
1177 | </listitem> |
1178 | </varlistentry> | |
452cfd98 LP |
1179 | </variablelist> |
1180 | </refsect1> | |
1181 | ||
c035f376 ZJS |
1182 | <refsect1> |
1183 | <title>Options</title> | |
1184 | ||
1185 | <para><command>systemd</command> is only very rarely invoked directly, since it is started early and is | |
1186 | already running by the time users may interact with it. Normally, tools like | |
1187 | <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> are used to | |
1188 | give commands to the manager. Since <command>systemd</command> is usually not invoked directly, the | |
1189 | options listed below are mostly useful for debugging and special purposes.</para> | |
1190 | ||
1191 | <refsect2> | |
1192 | <title>Introspection and debugging options</title> | |
1193 | ||
1194 | <para>Those options are used for testing and introspection, and <command>systemd</command> may | |
1195 | be invoked with them at any time:</para> | |
1196 | ||
1197 | <variablelist> | |
1198 | <varlistentry> | |
1199 | <term><option>--dump-configuration-items</option></term> | |
1200 | ||
1201 | <listitem><para>Dump understood unit configuration items. This outputs a terse but complete list of | |
1202 | configuration items understood in unit definition files.</para></listitem> | |
1203 | </varlistentry> | |
1204 | ||
1205 | <varlistentry> | |
1206 | <term><option>--dump-bus-properties</option></term> | |
1207 | ||
1208 | <listitem><para>Dump exposed bus properties. This outputs a terse but complete list of properties | |
aefdc112 AK |
1209 | exposed on D-Bus.</para> |
1210 | ||
1211 | <xi:include href="version-info.xml" xpointer="v239"/></listitem> | |
c035f376 ZJS |
1212 | </varlistentry> |
1213 | ||
1214 | <varlistentry> | |
1215 | <term><option>--test</option></term> | |
1216 | ||
1217 | <listitem><para>Determine the initial start-up transaction (i.e. the list of jobs enqueued at | |
1218 | start-up), dump it and exit — without actually executing any of the determined jobs. This option is | |
1219 | useful for debugging only. Note that during regular service manager start-up additional units not | |
1220 | shown by this operation may be started, because hardware, socket, bus or other kinds of activation | |
1221 | might add additional jobs as the transaction is executed. Use <option>--system</option> to request | |
1222 | the initial transaction of the system service manager (this is also the implied default), combine | |
1223 | with <option>--user</option> to request the initial transaction of the per-user service manager | |
1224 | instead.</para></listitem> | |
1225 | </varlistentry> | |
1226 | ||
1227 | <varlistentry> | |
1228 | <term><option>--system</option></term> | |
1229 | <term><option>--user</option></term> | |
1230 | ||
1231 | <listitem><para>When used in conjunction with <option>--test</option>, selects whether to calculate | |
1232 | the initial transaction for the system instance or for a per-user instance. These options have no | |
1233 | effect when invoked without <option>--test</option>, as during regular | |
1234 | (i.e. non-<option>--test</option>) invocations the service manager will automatically detect | |
1235 | whether it shall operate in system or per-user mode, by checking whether the PID it is run as is 1 | |
1236 | or not. Note that it is not supported booting and maintaining a system with the service manager | |
1237 | running in <option>--system</option> mode but with a PID other than 1.</para></listitem> | |
1238 | </varlistentry> | |
1239 | ||
1240 | <xi:include href="standard-options.xml" xpointer="help" /> | |
1241 | <xi:include href="standard-options.xml" xpointer="version" /> | |
1242 | </variablelist> | |
1243 | </refsect2> | |
1244 | ||
1245 | <refsect2> | |
1246 | <title>Options that duplicate kernel command line settings</title> | |
1247 | ||
1248 | <para>Those options correspond directly to options listed above in "Kernel Command Line". Both forms | |
1249 | may be used equivalently for the system manager, but it is recommended to use the forms listed above in | |
1250 | this context, because they are properly namespaced. When an option is specified both on the kernel | |
885a4e6c | 1251 | command line and as a normal command line argument, the latter has higher precedence.</para> |
c035f376 | 1252 | |
e9dd6984 | 1253 | <para>When <command>systemd</command> is used as a user manager, the kernel command line is ignored and |
ab1a8ff5 ZJS |
1254 | only the options described below are understood. Nevertheless, <command>systemd</command> is usually |
1255 | started in this mode through the | |
c035f376 | 1256 | <citerefentry><refentrytitle>user@.service</refentrytitle><manvolnum>5</manvolnum></citerefentry> |
d5158643 | 1257 | service, which is shared between all users. It may be more convenient to use configuration files to |
ab1a8ff5 ZJS |
1258 | modify settings (see |
1259 | <citerefentry><refentrytitle>systemd-user.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>), | |
d5158643 ZJS |
1260 | or environment variables. See the "Environment" section above for a discussion of how the environment |
1261 | block is set.</para> | |
c035f376 ZJS |
1262 | |
1263 | <variablelist> | |
1264 | <varlistentry> | |
1265 | <term><option>--unit=</option></term> | |
1266 | ||
1267 | <listitem><para>Set default unit to activate on startup. If not specified, defaults to | |
1268 | <filename>default.target</filename>. See <varname>systemd.unit=</varname> above.</para></listitem> | |
1269 | </varlistentry> | |
1270 | ||
1271 | <varlistentry> | |
1272 | <term><option>--dump-core</option></term> | |
1273 | ||
1274 | <listitem><para>Enable core dumping on crash. This switch has no effect when running as user | |
1275 | instance. Same as <varname>systemd.dump_core=</varname> above.</para></listitem> | |
1276 | </varlistentry> | |
1277 | ||
1278 | <varlistentry> | |
1279 | <term><option>--crash-vt=</option><replaceable>VT</replaceable></term> | |
1280 | ||
1281 | <listitem><para>Switch to a specific virtual console (VT) on crash. This switch has no effect when | |
1282 | running as user instance. Same as <varname>systemd.crash_chvt=</varname> above (but not the | |
aefdc112 AK |
1283 | different spelling!).</para> |
1284 | ||
1285 | <xi:include href="version-info.xml" xpointer="v227"/></listitem> | |
c035f376 ZJS |
1286 | </varlistentry> |
1287 | ||
1288 | <varlistentry> | |
1289 | <term><option>--crash-shell</option></term> | |
1290 | ||
1291 | <listitem><para>Run a shell on crash. This switch has no effect when running as user instance. See | |
1292 | <varname>systemd.crash_shell=</varname> above.</para></listitem> | |
1293 | </varlistentry> | |
1294 | ||
1295 | <varlistentry> | |
1296 | <term><option>--crash-reboot</option></term> | |
1297 | ||
1298 | <listitem><para>Automatically reboot the system on crash. This switch has no effect when running as | |
aefdc112 AK |
1299 | user instance. See <varname>systemd.crash_reboot</varname> above.</para> |
1300 | ||
1301 | <xi:include href="version-info.xml" xpointer="v227"/></listitem> | |
c035f376 ZJS |
1302 | </varlistentry> |
1303 | ||
1304 | <varlistentry> | |
1305 | <term><option>--confirm-spawn</option></term> | |
1306 | ||
1307 | <listitem><para>Ask for confirmation when spawning processes. This switch has no effect when run as | |
1308 | user instance. See <varname>systemd.confirm_spawn</varname> above.</para></listitem> | |
1309 | </varlistentry> | |
1310 | ||
1311 | <varlistentry> | |
1312 | <term><option>--show-status</option></term> | |
1313 | ||
e9dd6984 | 1314 | <listitem><para>Show terse unit status information on the console during boot-up and shutdown. See |
ec07c3c8 AK |
1315 | <varname>systemd.show_status</varname> above.</para> |
1316 | ||
1317 | <xi:include href="version-info.xml" xpointer="v244"/></listitem> | |
c035f376 ZJS |
1318 | </varlistentry> |
1319 | ||
1320 | <varlistentry> | |
3d5f0138 | 1321 | <term><option>--log-color</option></term> |
c035f376 | 1322 | |
3d5f0138 | 1323 | <listitem><para>Highlight important log messages. See <varname>systemd.log_color</varname> above. |
ec07c3c8 AK |
1324 | </para> |
1325 | ||
1326 | <xi:include href="version-info.xml" xpointer="v244"/></listitem> | |
c035f376 ZJS |
1327 | </varlistentry> |
1328 | ||
1329 | <varlistentry> | |
1330 | <term><option>--log-level=</option></term> | |
1331 | ||
1332 | <listitem><para>Set log level. See <varname>systemd.log_level</varname> above.</para></listitem> | |
1333 | </varlistentry> | |
1334 | ||
1335 | <varlistentry> | |
3d5f0138 | 1336 | <term><option>--log-location</option></term> |
c035f376 | 1337 | |
3d5f0138 | 1338 | <listitem><para>Include code location in log messages. See <varname>systemd.log_location</varname> |
ec07c3c8 AK |
1339 | above.</para> |
1340 | ||
1341 | <xi:include href="version-info.xml" xpointer="v244"/></listitem> | |
c035f376 ZJS |
1342 | </varlistentry> |
1343 | ||
1344 | <varlistentry> | |
3d5f0138 | 1345 | <term><option>--log-target=</option></term> |
c035f376 | 1346 | |
3d5f0138 | 1347 | <listitem><para>Set log target. See <varname>systemd.log_target</varname> above.</para></listitem> |
c035f376 ZJS |
1348 | </varlistentry> |
1349 | ||
1350 | <varlistentry> | |
c5673ed0 DS |
1351 | <term><option>--log-time=</option></term> |
1352 | ||
9f40351f | 1353 | <listitem><para>Prefix console messages with timestamp. See <varname>systemd.log_time</varname> above. |
ec07c3c8 AK |
1354 | </para> |
1355 | ||
1356 | <xi:include href="version-info.xml" xpointer="v246"/></listitem> | |
c035f376 ZJS |
1357 | </varlistentry> |
1358 | ||
1359 | <varlistentry> | |
1360 | <term><option>--machine-id=</option></term> | |
1361 | ||
1362 | <listitem><para>Override the machine-id set on the hard drive. See | |
aefdc112 AK |
1363 | <varname>systemd.machine_id=</varname> above.</para> |
1364 | ||
1365 | <xi:include href="version-info.xml" xpointer="v229"/></listitem> | |
c035f376 ZJS |
1366 | </varlistentry> |
1367 | ||
1368 | <varlistentry> | |
1369 | <term><option>--service-watchdogs</option></term> | |
1370 | ||
1371 | <listitem><para>Globally enable/disable all service watchdog timeouts and emergency actions. See | |
ec07c3c8 AK |
1372 | <varname>systemd.service_watchdogs</varname> above.</para> |
1373 | ||
aefdc112 | 1374 | <xi:include href="version-info.xml" xpointer="v237"/></listitem> |
c035f376 ZJS |
1375 | </varlistentry> |
1376 | ||
1377 | <varlistentry> | |
1378 | <term><option>--default-standard-output=</option></term> | |
1379 | <term><option>--default-standard-error=</option></term> | |
1380 | ||
1381 | <listitem><para>Sets the default output or error output for all services and sockets, | |
1382 | respectively. See <varname>systemd.default_standard_output=</varname> and | |
1383 | <varname>systemd.default_standard_error=</varname> above.</para></listitem> | |
1384 | </varlistentry> | |
1385 | </variablelist> | |
1386 | </refsect2> | |
1387 | </refsect1> | |
798d3a52 ZJS |
1388 | |
1389 | <refsect1> | |
1390 | <title>Sockets and FIFOs</title> | |
1391 | ||
1392 | <variablelist> | |
1393 | <varlistentry> | |
1394 | <term><filename>/run/systemd/notify</filename></term> | |
1395 | ||
1396 | <listitem><para>Daemon status notification socket. This is an | |
1397 | <constant>AF_UNIX</constant> datagram socket and is used to | |
1398 | implement the daemon notification logic as implemented by | |
1399 | <citerefentry><refentrytitle>sd_notify</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para></listitem> | |
1400 | ||
1401 | </varlistentry> | |
1402 | ||
798d3a52 ZJS |
1403 | <varlistentry> |
1404 | <term><filename>/run/systemd/private</filename></term> | |
1405 | ||
1406 | <listitem><para>Used internally as communication channel | |
1407 | between | |
1408 | <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry> | |
1409 | and the systemd process. This is an | |
1410 | <constant>AF_UNIX</constant> stream socket. This interface is | |
1411 | private to systemd and should not be used in external | |
1412 | projects.</para></listitem> | |
1413 | </varlistentry> | |
1414 | ||
1415 | <varlistentry> | |
1416 | <term><filename>/dev/initctl</filename></term> | |
1417 | ||
1418 | <listitem><para>Limited compatibility support for the SysV | |
1419 | client interface, as implemented by the | |
1420 | <filename>systemd-initctl.service</filename> unit. This is a | |
1421 | named pipe in the file system. This interface is obsolete and | |
1422 | should not be used in new applications.</para></listitem> | |
1423 | </varlistentry> | |
1424 | </variablelist> | |
1425 | </refsect1> | |
1426 | ||
7a9e0bd0 ZJS |
1427 | <refsect1> |
1428 | <title>History</title> | |
1429 | ||
1430 | <variablelist> | |
1431 | <varlistentry> | |
1432 | <term>systemd 252</term> | |
1433 | <listitem><para>Kernel command-line arguments <varname>systemd.unified_cgroup_hierarchy</varname> | |
1434 | and <varname>systemd.legacy_systemd_cgroup_controller</varname> were deprecated. Please switch to | |
ec07c3c8 AK |
1435 | the unified cgroup hierarchy.</para> |
1436 | ||
1437 | <xi:include href="version-info.xml" xpointer="v252"/></listitem> | |
7a9e0bd0 ZJS |
1438 | </varlistentry> |
1439 | </variablelist> | |
1440 | </refsect1> | |
1441 | ||
798d3a52 ZJS |
1442 | <refsect1> |
1443 | <title>See Also</title> | |
1444 | <para> | |
a8c03388 | 1445 | The <ulink url="https://systemd.io/">systemd Homepage</ulink>, |
798d3a52 | 1446 | <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>, |
3ba3a79d | 1447 | <citerefentry project='man-pages'><refentrytitle>locale.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>, |
798d3a52 ZJS |
1448 | <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, |
1449 | <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
1450 | <citerefentry><refentrytitle>systemd-notify</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
1451 | <citerefentry><refentrytitle>daemon</refentrytitle><manvolnum>7</manvolnum></citerefentry>, | |
1452 | <citerefentry><refentrytitle>sd-daemon</refentrytitle><manvolnum>3</manvolnum></citerefentry>, | |
3031660c | 1453 | <citerefentry><refentrytitle>org.freedesktop.systemd1</refentrytitle><manvolnum>5</manvolnum></citerefentry>, |
798d3a52 | 1454 | <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>, |
675fa6ea | 1455 | <citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>, |
798d3a52 ZJS |
1456 | <citerefentry project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>, |
1457 | <citerefentry><refentrytitle>kernel-command-line</refentrytitle><manvolnum>7</manvolnum></citerefentry>, | |
1458 | <citerefentry project='man-pages'><refentrytitle>bootup</refentrytitle><manvolnum>7</manvolnum></citerefentry>, | |
1459 | <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry> | |
1460 | </para> | |
1461 | </refsect1> | |
9e632bf7 LP |
1462 | |
1463 | </refentry> |