man/systemd-system.conf.xml

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  11   Copyright 2010 Lennart Poettering
  12 -->
  13
  14 <refentry id="systemd-system.conf"
  15     xmlns:xi="http://www.w3.org/2001/XInclude">
  16   <refentryinfo>
  17     <title>systemd-system.conf</title>
  18     <productname>systemd</productname>
  19
  20     <authorgroup>
  21       <author>
  22         <contrib>Developer</contrib>
  23         <firstname>Lennart</firstname>
  24         <surname>Poettering</surname>
  25         <email>lennart@poettering.net</email>
  26       </author>
  27     </authorgroup>
  28   </refentryinfo>
  29
  30   <refmeta>
  31     <refentrytitle>systemd-system.conf</refentrytitle>
  32     <manvolnum>5</manvolnum>
  33   </refmeta>
  34
  35   <refnamediv>
  36     <refname>systemd-system.conf</refname>
  37     <refname>system.conf.d</refname>
  38     <refname>systemd-user.conf</refname>
  39     <refname>user.conf.d</refname>
  40     <refpurpose>System and session service manager configuration files</refpurpose>
  41   </refnamediv>
  42
  43   <refsynopsisdiv>
  44     <para><filename>/etc/systemd/system.conf</filename>,
  45     <filename>/etc/systemd/system.conf.d/*.conf</filename>,
  46     <filename>/run/systemd/system.conf.d/*.conf</filename>,
  47     <filename>/usr/lib/systemd/system.conf.d/*.conf</filename></para>
  48     <para><filename>/etc/systemd/user.conf</filename>,
  49     <filename>/etc/systemd/user.conf.d/*.conf</filename>,
  50     <filename>/run/systemd/user.conf.d/*.conf</filename>,
  51     <filename>/usr/lib/systemd/user.conf.d/*.conf</filename></para>
  52   </refsynopsisdiv>
  53
  54   <refsect1>
  55     <title>Description</title>
  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. These configuration
  63     files contain a few settings controlling basic manager
  64     operations. See
  65     <citerefentry><refentrytitle>systemd.syntax</refentrytitle><manvolnum>5</manvolnum></citerefentry>
  66     for a general description of the syntax.</para>
  67   </refsect1>
  68
  69   <xi:include href="standard-conf.xml" xpointer="main-conf" />
  70
  71   <refsect1>
  72     <title>Options</title>
  73
  74     <para>All options are configured in the
  75     <literal>[Manager]</literal> section:</para>
  76
  77     <variablelist class='systemd-directives'>
  78
  79       <varlistentry>
  80         <term><varname>LogLevel=</varname></term>
  81         <term><varname>LogTarget=</varname></term>
  82         <term><varname>LogColor=</varname></term>
  83         <term><varname>LogLocation=</varname></term>
  84         <term><varname>DumpCore=yes</varname></term>
  85         <term><varname>CrashChangeVT=no</varname></term>
  86         <term><varname>CrashShell=no</varname></term>
  87         <term><varname>CrashReboot=no</varname></term>
  88         <term><varname>ShowStatus=yes</varname></term>
  89         <term><varname>DefaultStandardOutput=journal</varname></term>
  90         <term><varname>DefaultStandardError=inherit</varname></term>
  91
  92         <listitem><para>Configures various parameters of basic manager operation. These options may be overridden by
  93         the respective process and kernel command line arguments. See
  94         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry> for
  95         details.</para></listitem>
  96       </varlistentry>
  97
  98       <varlistentry>
  99         <term><varname>CtrlAltDelBurstAction=</varname></term>
 100
 101         <listitem><para>Defines what action will be performed
 102         if user presses Ctrl-Alt-Delete more than 7 times in 2s.
 103         Can be set to <literal>reboot-force</literal>, <literal>poweroff-force</literal>,
 104         <literal>reboot-immediate</literal>, <literal>poweroff-immediate</literal>
 105         or disabled with <literal>none</literal>. Defaults to
 106         <literal>reboot-force</literal>.
 107         </para></listitem>
 108       </varlistentry>
 109
 110       <varlistentry>
 111         <term><varname>CPUAffinity=</varname></term>
 112
 113         <listitem><para>Configures the initial CPU affinity for the
 114         init process. Takes a list of CPU indices or ranges separated
 115         by either whitespace or commas. CPU ranges are specified by
 116         the lower and upper CPU indices separated by a
 117         dash.</para></listitem>
 118       </varlistentry>
 119
 120       <varlistentry>
 121         <term><varname>JoinControllers=cpu,cpuacct net_cls,netprio</varname></term>
 122
 123         <listitem><para>Configures controllers that shall be mounted
 124         in a single hierarchy. By default, systemd will mount all
 125         controllers which are enabled in the kernel in individual
 126         hierarchies, with the exception of those listed in this
 127         setting. Takes a space-separated list of comma-separated
 128         controller names, in order to allow multiple joined
 129         hierarchies. Defaults to 'cpu,cpuacct'. Pass an empty string
 130         to ensure that systemd mounts all controllers in separate
 131         hierarchies.</para>
 132
 133         <para>Note that this option is only applied once, at very
 134         early boot. If you use an initial RAM disk (initrd) that uses
 135         systemd, it might hence be necessary to rebuild the initrd if
 136         this option is changed, and make sure the new configuration
 137         file is included in it. Otherwise, the initrd might mount the
 138         controller hierarchies in a different configuration than
 139         intended, and the main system cannot remount them
 140         anymore.</para></listitem>
 141       </varlistentry>
 142
 143       <varlistentry>
 144         <term><varname>RuntimeWatchdogSec=</varname></term>
 145         <term><varname>ShutdownWatchdogSec=</varname></term>
 146
 147         <listitem><para>Configure the hardware watchdog at runtime and at reboot. Takes a timeout value in seconds (or
 148         in other time units if suffixed with <literal>ms</literal>, <literal>min</literal>, <literal>h</literal>,
 149         <literal>d</literal>, <literal>w</literal>). If <varname>RuntimeWatchdogSec=</varname> is set to a non-zero
 150         value, the watchdog hardware (<filename>/dev/watchdog</filename> or the path specified with
 151         <varname>WatchdogDevice=</varname> or the kernel option <varname>systemd.watchdog-device=</varname>) will be
 152         programmed to automatically reboot the system if it is not contacted within the specified timeout interval. The
 153         system manager will ensure to contact it at least once in half the specified timeout interval. This feature
 154         requires a hardware watchdog device to be present, as it is commonly the case in embedded and server
 155         systems. Not all hardware watchdogs allow configuration of all possible reboot timeout values, in which case
 156         the closest available timeout is picked. <varname>ShutdownWatchdogSec=</varname> may be used to configure the
 157         hardware watchdog when the system is asked to reboot. It works as a safety net to ensure that the reboot takes
 158         place even if a clean reboot attempt times out. Note that the <varname>ShutdownWatchdogSec=</varname> timeout
 159         applies only to the second phase of the reboot, i.e. after all regular services are already terminated, and
 160         after the system and service manager process (PID 1) got replaced by the <filename>systemd-shutdown</filename>
 161         binary, see system <citerefentry><refentrytitle>bootup</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 162         for details. During the first phase of the shutdown operation the system and service manager remains running
 163         and hence <varname>RuntimeWatchdogSec=</varname> is still honoured. In order to define a timeout on this first
 164         phase of system shutdown, configure <varname>JobTimeoutSec=</varname> and <varname>JobTimeoutAction=</varname>
 165         in the <literal>[Unit]</literal> section of the <filename>shutdown.target</filename> unit. By default
 166         <varname>RuntimeWatchdogSec=</varname> defaults to 0 (off), and <varname>ShutdownWatchdogSec=</varname> to
 167         10min. These settings have no effect if a hardware watchdog is not available.</para></listitem>
 168       </varlistentry>
 169
 170       <varlistentry>
 171         <term><varname>WatchdogDevice=</varname></term>
 172
 173         <listitem><para>Configure the hardware watchdog device that the
 174         runtime and shutdown watchdog timers will open and use. Defaults
 175         to <filename>/dev/watchdog</filename>. This setting has no
 176         effect if a hardware watchdog is not available.</para></listitem>
 177       </varlistentry>
 178
 179       <varlistentry>
 180         <term><varname>CapabilityBoundingSet=</varname></term>
 181
 182         <listitem><para>Controls which capabilities to include in the
 183         capability bounding set for PID 1 and its children. See
 184         <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 185         for details. Takes a whitespace-separated list of capability
 186         names as read by
 187         <citerefentry project='mankier'><refentrytitle>cap_from_name</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
 188         Capabilities listed will be included in the bounding set, all
 189         others are removed. If the list of capabilities is prefixed
 190         with ~, all but the listed capabilities will be included, the
 191         effect of the assignment inverted. Note that this option also
 192         affects the respective capabilities in the effective,
 193         permitted and inheritable capability sets. The capability
 194         bounding set may also be individually configured for units
 195         using the <varname>CapabilityBoundingSet=</varname> directive
 196         for units, but note that capabilities dropped for PID 1 cannot
 197         be regained in individual units, they are lost for
 198         good.</para></listitem>
 199       </varlistentry>
 200
 201       <varlistentry>
 202         <term><varname>NoNewPrivileges=</varname></term>
 203
 204         <listitem><para>Takes a boolean argument. If true, ensures that PID 1
 205         and all its children can never gain new privileges through
 206         <citerefentry project='man-pages'><refentrytitle>execve</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 207         (e.g. via setuid or setgid bits, or filesystem capabilities).
 208         Defaults to false. General purpose distributions commonly rely
 209         on executables with setuid or setgid bits and will thus not
 210         function properly with this option enabled. Individual units
 211         cannot disable this option.
 212         Also see <ulink url="https://www.kernel.org/doc/html/latest/userspace-api/no_new_privs.html">No New Privileges Flag</ulink>.
 213         </para></listitem>
 214       </varlistentry>
 215
 216       <varlistentry>
 217         <term><varname>SystemCallArchitectures=</varname></term>
 218
 219         <listitem><para>Takes a space-separated list of architecture
 220         identifiers. Selects from which architectures system calls may
 221         be invoked on this system. This may be used as an effective
 222         way to disable invocation of non-native binaries system-wide,
 223         for example to prohibit execution of 32-bit x86 binaries on
 224         64-bit x86-64 systems. This option operates system-wide, and
 225         acts similar to the
 226         <varname>SystemCallArchitectures=</varname> setting of unit
 227         files, see
 228         <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 229         for details. This setting defaults to the empty list, in which
 230         case no filtering of system calls based on architecture is
 231         applied. Known architecture identifiers are
 232         <literal>x86</literal>, <literal>x86-64</literal>,
 233         <literal>x32</literal>, <literal>arm</literal> and the special
 234         identifier <literal>native</literal>. The latter implicitly
 235         maps to the native architecture of the system (or more
 236         specifically, the architecture the system manager was compiled
 237         for). Set this setting to <literal>native</literal> to
 238         prohibit execution of any non-native binaries. When a binary
 239         executes a system call of an architecture that is not listed
 240         in this setting, it will be immediately terminated with the
 241         SIGSYS signal.</para></listitem>
 242       </varlistentry>
 243
 244       <varlistentry>
 245         <term><varname>TimerSlackNSec=</varname></term>
 246
 247         <listitem><para>Sets the timer slack in nanoseconds for PID 1,
 248         which is inherited by all executed processes, unless
 249         overridden individually, for example with the
 250         <varname>TimerSlackNSec=</varname> setting in service units
 251         (for details see
 252         <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>).
 253         The timer slack controls the accuracy of wake-ups triggered by
 254         system timers. See
 255         <citerefentry><refentrytitle>prctl</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 256         for more information. Note that in contrast to most other time
 257         span definitions this parameter takes an integer value in
 258         nano-seconds if no unit is specified. The usual time units are
 259         understood too.</para></listitem>
 260       </varlistentry>
 261
 262       <varlistentry>
 263         <term><varname>DefaultTimerAccuracySec=</varname></term>
 264
 265         <listitem><para>Sets the default accuracy of timer units. This
 266         controls the global default for the
 267         <varname>AccuracySec=</varname> setting of timer units, see
 268         <citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 269         for details. <varname>AccuracySec=</varname> set in individual
 270         units override the global default for the specific unit.
 271         Defaults to 1min. Note that the accuracy of timer units is
 272         also affected by the configured timer slack for PID 1, see
 273         <varname>TimerSlackNSec=</varname> above.</para></listitem>
 274       </varlistentry>
 275
 276       <varlistentry>
 277         <term><varname>DefaultTimeoutStartSec=</varname></term>
 278         <term><varname>DefaultTimeoutStopSec=</varname></term>
 279         <term><varname>DefaultRestartSec=</varname></term>
 280
 281         <listitem><para>Configures the default timeouts for starting
 282         and stopping of units, as well as the default time to sleep
 283         between automatic restarts of units, as configured per-unit in
 284         <varname>TimeoutStartSec=</varname>,
 285         <varname>TimeoutStopSec=</varname> and
 286         <varname>RestartSec=</varname> (for services, see
 287         <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 288         for details on the per-unit settings). For non-service units,
 289         <varname>DefaultTimeoutStartSec=</varname> sets the default
 290         <varname>TimeoutSec=</varname>
 291         value. <varname>DefaultTimeoutStartSec=</varname> and
 292         <varname>DefaultTimeoutStopSec=</varname> default to
 293         90s. <varname>DefaultRestartSec=</varname> defaults to
 294         100ms.</para></listitem>
 295       </varlistentry>
 296
 297       <varlistentry>
 298         <term><varname>DefaultStartLimitIntervalSec=</varname></term>
 299         <term><varname>DefaultStartLimitBurst=</varname></term>
 300
 301         <listitem><para>Configure the default unit start rate
 302         limiting, as configured per-service by
 303         <varname>StartLimitIntervalSec=</varname> and
 304         <varname>StartLimitBurst=</varname>. See
 305         <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 306         for details on the per-service settings.
 307         <varname>DefaultStartLimitIntervalSec=</varname> defaults to
 308         10s. <varname>DefaultStartLimitBurst=</varname> defaults to
 309         5.</para></listitem>
 310       </varlistentry>
 311
 312       <varlistentry>
 313         <term><varname>DefaultEnvironment=</varname></term>
 314
 315         <listitem><para>Sets manager environment variables passed to
 316         all executed processes. Takes a space-separated list of
 317         variable assignments. See
 318         <citerefentry project='man-pages'><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 319         for details about environment variables.</para>
 320
 321         <para>Example:
 322
 323         <programlisting>DefaultEnvironment="VAR1=word1 word2" VAR2=word3 "VAR3=word 5 6"</programlisting>
 324
 325         Sets three variables
 326         <literal>VAR1</literal>,
 327         <literal>VAR2</literal>,
 328         <literal>VAR3</literal>.</para></listitem>
 329       </varlistentry>
 330
 331       <varlistentry>
 332         <term><varname>DefaultCPUAccounting=</varname></term>
 333         <term><varname>DefaultBlockIOAccounting=</varname></term>
 334         <term><varname>DefaultMemoryAccounting=</varname></term>
 335         <term><varname>DefaultTasksAccounting=</varname></term>
 336         <term><varname>DefaultIPAccounting=</varname></term>
 337
 338         <listitem><para>Configure the default resource accounting settings, as configured per-unit by
 339         <varname>CPUAccounting=</varname>, <varname>BlockIOAccounting=</varname>, <varname>MemoryAccounting=</varname>,
 340         <varname>TasksAccounting=</varname> and <varname>IPAccounting=</varname>. See
 341         <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 342         for details on the per-unit settings. <varname>DefaultTasksAccounting=</varname> defaults to on,
 343         <varname>DefaultMemoryAccounting=</varname> to &MEMORY_ACCOUNTING_DEFAULT;,
 344         the other three settings to off.</para></listitem>
 345       </varlistentry>
 346
 347       <varlistentry>
 348         <term><varname>DefaultTasksMax=</varname></term>
 349
 350         <listitem><para>Configure the default value for the per-unit <varname>TasksMax=</varname> setting. See
 351         <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 352         for details. This setting applies to all unit types that support resource control settings, with the exception
 353         of slice units. Defaults to 15%, which equals 4915 with the kernel's defaults on the host, but might be smaller
 354         in OS containers.</para></listitem>
 355       </varlistentry>
 356
 357       <varlistentry>
 358         <term><varname>DefaultLimitCPU=</varname></term>
 359         <term><varname>DefaultLimitFSIZE=</varname></term>
 360         <term><varname>DefaultLimitDATA=</varname></term>
 361         <term><varname>DefaultLimitSTACK=</varname></term>
 362         <term><varname>DefaultLimitCORE=</varname></term>
 363         <term><varname>DefaultLimitRSS=</varname></term>
 364         <term><varname>DefaultLimitNOFILE=</varname></term>
 365         <term><varname>DefaultLimitAS=</varname></term>
 366         <term><varname>DefaultLimitNPROC=</varname></term>
 367         <term><varname>DefaultLimitMEMLOCK=</varname></term>
 368         <term><varname>DefaultLimitLOCKS=</varname></term>
 369         <term><varname>DefaultLimitSIGPENDING=</varname></term>
 370         <term><varname>DefaultLimitMSGQUEUE=</varname></term>
 371         <term><varname>DefaultLimitNICE=</varname></term>
 372         <term><varname>DefaultLimitRTPRIO=</varname></term>
 373         <term><varname>DefaultLimitRTTIME=</varname></term>
 374
 375         <listitem><para>These settings control various default
 376         resource limits for units. See
 377         <citerefentry><refentrytitle>setrlimit</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 378         for details. The resource limit is possible to specify in two formats,
 379         <option>value</option> to set soft and hard limits to the same value,
 380         or <option>soft:hard</option> to set both limits individually (e.g. DefaultLimitAS=4G:16G).
 381         Use the string <varname>infinity</varname> to
 382         configure no limit on a specific resource. The multiplicative
 383         suffixes K (=1024), M (=1024*1024) and so on for G, T, P and E
 384         may be used for resource limits measured in bytes
 385         (e.g. DefaultLimitAS=16G). For the limits referring to time values,
 386         the usual time units ms, s, min, h and so on may be used (see
 387         <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 388         for details). Note that if no time unit is specified for
 389         <varname>DefaultLimitCPU=</varname> the default unit of seconds is
 390         implied, while for <varname>DefaultLimitRTTIME=</varname> the default
 391         unit of microseconds is implied. Also, note that the effective
 392         granularity of the limits might influence their
 393         enforcement. For example, time limits specified for
 394         <varname>DefaultLimitCPU=</varname> will be rounded up implicitly to
 395         multiples of 1s. These  settings may be overridden in individual units
 396         using the corresponding LimitXXX= directives. Note that these resource
 397         limits are only defaults for units, they are not applied to PID 1
 398         itself.</para></listitem>
 399       </varlistentry>
 400     </variablelist>
 401   </refsect1>
 402
 403   <refsect1>
 404       <title>See Also</title>
 405       <para>
 406         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 407         <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
 408         <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 409         <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 410         <citerefentry project='man-pages'><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
 411         <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 412       </para>
 413   </refsect1>
 414
 415 </refentry>