man/systemd-system.conf.xml

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   8
   9 <refentry id="systemd-system.conf"
  10     xmlns:xi="http://www.w3.org/2001/XInclude">
  11   <refentryinfo>
  12     <title>systemd-system.conf</title>
  13     <productname>systemd</productname>
  14   </refentryinfo>
  15
  16   <refmeta>
  17     <refentrytitle>systemd-system.conf</refentrytitle>
  18     <manvolnum>5</manvolnum>
  19   </refmeta>
  20
  21   <refnamediv>
  22     <refname>systemd-system.conf</refname>
  23     <refname>system.conf.d</refname>
  24     <refname>systemd-user.conf</refname>
  25     <refname>user.conf.d</refname>
  26     <refpurpose>System and session service manager configuration files</refpurpose>
  27   </refnamediv>
  28
  29   <refsynopsisdiv>
  30     <para><filename>/etc/systemd/system.conf</filename>,
  31     <filename>/etc/systemd/system.conf.d/*.conf</filename>,
  32     <filename>/run/systemd/system.conf.d/*.conf</filename>,
  33     <filename>/usr/lib/systemd/system.conf.d/*.conf</filename></para>
  34     <para><filename>/etc/systemd/user.conf</filename>,
  35     <filename>/etc/systemd/user.conf.d/*.conf</filename>,
  36     <filename>/run/systemd/user.conf.d/*.conf</filename>,
  37     <filename>/usr/lib/systemd/user.conf.d/*.conf</filename></para>
  38   </refsynopsisdiv>
  39
  40   <refsect1>
  41     <title>Description</title>
  42
  43     <para>When run as a system instance, systemd interprets the
  44     configuration file <filename>system.conf</filename> and the files
  45     in <filename>system.conf.d</filename> directories; when run as a
  46     user instance, systemd interprets the configuration file
  47     <filename>user.conf</filename> and the files in
  48     <filename>user.conf.d</filename> directories. These configuration
  49     files contain a few settings controlling basic manager
  50     operations. See
  51     <citerefentry><refentrytitle>systemd.syntax</refentrytitle><manvolnum>5</manvolnum></citerefentry>
  52     for a general description of the syntax.</para>
  53   </refsect1>
  54
  55   <xi:include href="standard-conf.xml" xpointer="main-conf" />
  56
  57   <refsect1>
  58     <title>Options</title>
  59
  60     <para>All options are configured in the
  61     <literal>[Manager]</literal> section:</para>
  62
  63     <variablelist class='config-directives'>
  64
  65       <varlistentry>
  66         <term><varname>LogLevel=</varname></term>
  67         <term><varname>LogTarget=</varname></term>
  68         <term><varname>LogColor=</varname></term>
  69         <term><varname>LogLocation=</varname></term>
  70         <term><varname>DumpCore=yes</varname></term>
  71         <term><varname>CrashChangeVT=no</varname></term>
  72         <term><varname>CrashShell=no</varname></term>
  73         <term><varname>CrashReboot=no</varname></term>
  74         <term><varname>ShowStatus=yes</varname></term>
  75         <term><varname>DefaultStandardOutput=journal</varname></term>
  76         <term><varname>DefaultStandardError=inherit</varname></term>
  77
  78         <listitem><para>Configures various parameters of basic manager operation. These options may be overridden by
  79         the respective process and kernel command line arguments. See
  80         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry> for
  81         details.</para></listitem>
  82       </varlistentry>
  83
  84       <varlistentry>
  85         <term><varname>CtrlAltDelBurstAction=</varname></term>
  86
  87         <listitem><para>Defines what action will be performed
  88         if user presses Ctrl-Alt-Delete more than 7 times in 2s.
  89         Can be set to <literal>reboot-force</literal>, <literal>poweroff-force</literal>,
  90         <literal>reboot-immediate</literal>, <literal>poweroff-immediate</literal>
  91         or disabled with <literal>none</literal>. Defaults to
  92         <literal>reboot-force</literal>.
  93         </para></listitem>
  94       </varlistentry>
  95
  96       <varlistentry>
  97         <term><varname>CPUAffinity=</varname></term>
  98
  99         <listitem><para>Configures the CPU affinity for the service manager as well as the default CPU affinity for all
 100         forked off processes. Takes a list of CPU indices or ranges separated by either whitespace or commas. CPU
 101         ranges are specified by the lower and upper CPU indices separated by a dash. Individual services may override
 102         the CPU affinity for their processes with the <varname>CPUAffinity=</varname> setting in unit files, see
 103         <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem>
 104       </varlistentry>
 105
 106       <varlistentry>
 107         <term><varname>RuntimeWatchdogSec=</varname></term>
 108         <term><varname>ShutdownWatchdogSec=</varname></term>
 109
 110         <listitem><para>Configure the hardware watchdog at runtime and at reboot. Takes a timeout value in seconds (or
 111         in other time units if suffixed with <literal>ms</literal>, <literal>min</literal>, <literal>h</literal>,
 112         <literal>d</literal>, <literal>w</literal>). If <varname>RuntimeWatchdogSec=</varname> is set to a non-zero
 113         value, the watchdog hardware (<filename>/dev/watchdog</filename> or the path specified with
 114         <varname>WatchdogDevice=</varname> or the kernel option <varname>systemd.watchdog-device=</varname>) will be
 115         programmed to automatically reboot the system if it is not contacted within the specified timeout interval. The
 116         system manager will ensure to contact it at least once in half the specified timeout interval. This feature
 117         requires a hardware watchdog device to be present, as it is commonly the case in embedded and server
 118         systems. Not all hardware watchdogs allow configuration of all possible reboot timeout values, in which case
 119         the closest available timeout is picked. <varname>ShutdownWatchdogSec=</varname> may be used to configure the
 120         hardware watchdog when the system is asked to reboot. It works as a safety net to ensure that the reboot takes
 121         place even if a clean reboot attempt times out. Note that the <varname>ShutdownWatchdogSec=</varname> timeout
 122         applies only to the second phase of the reboot, i.e. after all regular services are already terminated, and
 123         after the system and service manager process (PID 1) got replaced by the <filename>systemd-shutdown</filename>
 124         binary, see system <citerefentry><refentrytitle>bootup</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 125         for details. During the first phase of the shutdown operation the system and service manager remains running
 126         and hence <varname>RuntimeWatchdogSec=</varname> is still honoured. In order to define a timeout on this first
 127         phase of system shutdown, configure <varname>JobTimeoutSec=</varname> and <varname>JobTimeoutAction=</varname>
 128         in the <literal>[Unit]</literal> section of the <filename>shutdown.target</filename> unit. By default
 129         <varname>RuntimeWatchdogSec=</varname> defaults to 0 (off), and <varname>ShutdownWatchdogSec=</varname> to
 130         10min. These settings have no effect if a hardware watchdog is not available.</para></listitem>
 131       </varlistentry>
 132
 133       <varlistentry>
 134         <term><varname>WatchdogDevice=</varname></term>
 135
 136         <listitem><para>Configure the hardware watchdog device that the
 137         runtime and shutdown watchdog timers will open and use. Defaults
 138         to <filename>/dev/watchdog</filename>. This setting has no
 139         effect if a hardware watchdog is not available.</para></listitem>
 140       </varlistentry>
 141
 142       <varlistentry>
 143         <term><varname>CapabilityBoundingSet=</varname></term>
 144
 145         <listitem><para>Controls which capabilities to include in the
 146         capability bounding set for PID 1 and its children. See
 147         <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 148         for details. Takes a whitespace-separated list of capability
 149         names as read by
 150         <citerefentry project='mankier'><refentrytitle>cap_from_name</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
 151         Capabilities listed will be included in the bounding set, all
 152         others are removed. If the list of capabilities is prefixed
 153         with ~, all but the listed capabilities will be included, the
 154         effect of the assignment inverted. Note that this option also
 155         affects the respective capabilities in the effective,
 156         permitted and inheritable capability sets. The capability
 157         bounding set may also be individually configured for units
 158         using the <varname>CapabilityBoundingSet=</varname> directive
 159         for units, but note that capabilities dropped for PID 1 cannot
 160         be regained in individual units, they are lost for
 161         good.</para></listitem>
 162       </varlistentry>
 163
 164       <varlistentry>
 165         <term><varname>NoNewPrivileges=</varname></term>
 166
 167         <listitem><para>Takes a boolean argument. If true, ensures that PID 1
 168         and all its children can never gain new privileges through
 169         <citerefentry project='man-pages'><refentrytitle>execve</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 170         (e.g. via setuid or setgid bits, or filesystem capabilities).
 171         Defaults to false. General purpose distributions commonly rely
 172         on executables with setuid or setgid bits and will thus not
 173         function properly with this option enabled. Individual units
 174         cannot disable this option.
 175         Also see <ulink url="https://www.kernel.org/doc/html/latest/userspace-api/no_new_privs.html">No New Privileges Flag</ulink>.
 176         </para></listitem>
 177       </varlistentry>
 178
 179       <varlistentry>
 180         <term><varname>SystemCallArchitectures=</varname></term>
 181
 182         <listitem><para>Takes a space-separated list of architecture
 183         identifiers. Selects from which architectures system calls may
 184         be invoked on this system. This may be used as an effective
 185         way to disable invocation of non-native binaries system-wide,
 186         for example to prohibit execution of 32-bit x86 binaries on
 187         64-bit x86-64 systems. This option operates system-wide, and
 188         acts similar to the
 189         <varname>SystemCallArchitectures=</varname> setting of unit
 190         files, see
 191         <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 192         for details. This setting defaults to the empty list, in which
 193         case no filtering of system calls based on architecture is
 194         applied. Known architecture identifiers are
 195         <literal>x86</literal>, <literal>x86-64</literal>,
 196         <literal>x32</literal>, <literal>arm</literal> and the special
 197         identifier <literal>native</literal>. The latter implicitly
 198         maps to the native architecture of the system (or more
 199         specifically, the architecture the system manager was compiled
 200         for). Set this setting to <literal>native</literal> to
 201         prohibit execution of any non-native binaries. When a binary
 202         executes a system call of an architecture that is not listed
 203         in this setting, it will be immediately terminated with the
 204         SIGSYS signal.</para></listitem>
 205       </varlistentry>
 206
 207       <varlistentry>
 208         <term><varname>TimerSlackNSec=</varname></term>
 209
 210         <listitem><para>Sets the timer slack in nanoseconds for PID 1,
 211         which is inherited by all executed processes, unless
 212         overridden individually, for example with the
 213         <varname>TimerSlackNSec=</varname> setting in service units
 214         (for details see
 215         <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>).
 216         The timer slack controls the accuracy of wake-ups triggered by
 217         system timers. See
 218         <citerefentry><refentrytitle>prctl</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 219         for more information. Note that in contrast to most other time
 220         span definitions this parameter takes an integer value in
 221         nano-seconds if no unit is specified. The usual time units are
 222         understood too.</para></listitem>
 223       </varlistentry>
 224
 225       <varlistentry>
 226         <term><varname>DefaultTimerAccuracySec=</varname></term>
 227
 228         <listitem><para>Sets the default accuracy of timer units. This
 229         controls the global default for the
 230         <varname>AccuracySec=</varname> setting of timer units, see
 231         <citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 232         for details. <varname>AccuracySec=</varname> set in individual
 233         units override the global default for the specific unit.
 234         Defaults to 1min. Note that the accuracy of timer units is
 235         also affected by the configured timer slack for PID 1, see
 236         <varname>TimerSlackNSec=</varname> above.</para></listitem>
 237       </varlistentry>
 238
 239       <varlistentry>
 240         <term><varname>DefaultTimeoutStartSec=</varname></term>
 241         <term><varname>DefaultTimeoutStopSec=</varname></term>
 242         <term><varname>DefaultTimeoutAbortSec=</varname></term>
 243         <term><varname>DefaultRestartSec=</varname></term>
 244
 245         <listitem><para>Configures the default timeouts for starting,
 246         stopping and aborting of units, as well as the default time to sleep
 247         between automatic restarts of units, as configured per-unit in
 248         <varname>TimeoutStartSec=</varname>,
 249         <varname>TimeoutStopSec=</varname>,
 250         <varname>TimeoutAbortSec=</varname> and
 251         <varname>RestartSec=</varname> (for services, see
 252         <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 253         for details on the per-unit settings). Disabled by default, when
 254         service with <varname>Type=oneshot</varname> is used.
 255         For non-service units,
 256         <varname>DefaultTimeoutStartSec=</varname> sets the default
 257         <varname>TimeoutSec=</varname>
 258         value. <varname>DefaultTimeoutStartSec=</varname> and
 259         <varname>DefaultTimeoutStopSec=</varname> default to
 260         90s. <varname>DefaultTimeoutAbortSec=</varname> is not set by default
 261         so that all units fall back to <varname>TimeoutStopSec=</varname>.
 262         <varname>DefaultRestartSec=</varname> defaults to
 263         100ms.</para></listitem>
 264       </varlistentry>
 265
 266       <varlistentry>
 267         <term><varname>DefaultStartLimitIntervalSec=</varname></term>
 268         <term><varname>DefaultStartLimitBurst=</varname></term>
 269
 270         <listitem><para>Configure the default unit start rate
 271         limiting, as configured per-service by
 272         <varname>StartLimitIntervalSec=</varname> and
 273         <varname>StartLimitBurst=</varname>. See
 274         <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 275         for details on the per-service settings.
 276         <varname>DefaultStartLimitIntervalSec=</varname> defaults to
 277         10s. <varname>DefaultStartLimitBurst=</varname> defaults to
 278         5.</para></listitem>
 279       </varlistentry>
 280
 281       <varlistentry>
 282         <term><varname>DefaultEnvironment=</varname></term>
 283
 284         <listitem><para>Sets manager environment variables passed to
 285         all executed processes. Takes a space-separated list of
 286         variable assignments. See
 287         <citerefentry project='man-pages'><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 288         for details about environment variables.</para>
 289
 290         <para>Example:
 291
 292         <programlisting>DefaultEnvironment="VAR1=word1 word2" VAR2=word3 "VAR3=word 5 6"</programlisting>
 293
 294         Sets three variables
 295         <literal>VAR1</literal>,
 296         <literal>VAR2</literal>,
 297         <literal>VAR3</literal>.</para></listitem>
 298       </varlistentry>
 299
 300       <varlistentry>
 301         <term><varname>DefaultCPUAccounting=</varname></term>
 302         <term><varname>DefaultBlockIOAccounting=</varname></term>
 303         <term><varname>DefaultMemoryAccounting=</varname></term>
 304         <term><varname>DefaultTasksAccounting=</varname></term>
 305         <term><varname>DefaultIOAccounting=</varname></term>
 306         <term><varname>DefaultIPAccounting=</varname></term>
 307
 308         <listitem><para>Configure the default resource accounting settings, as configured per-unit by
 309         <varname>CPUAccounting=</varname>, <varname>BlockIOAccounting=</varname>, <varname>MemoryAccounting=</varname>,
 310         <varname>TasksAccounting=</varname>, <varname>IOAccounting=</varname> and <varname>IPAccounting=</varname>. See
 311         <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 312         for details on the per-unit settings. <varname>DefaultTasksAccounting=</varname> defaults to yes,
 313         <varname>DefaultMemoryAccounting=</varname> to &MEMORY_ACCOUNTING_DEFAULT;. <varname>DefaultCPUAccounting=</varname>
 314         defaults to yes if enabling CPU accounting doesn't require the CPU controller to be enabled (Linux 4.15+ using the
 315         unified hierarchy for resource control), otherwise it defaults to no. The other three settings default to no.</para></listitem>
 316       </varlistentry>
 317
 318       <varlistentry>
 319         <term><varname>DefaultTasksMax=</varname></term>
 320
 321         <listitem><para>Configure the default value for the per-unit <varname>TasksMax=</varname> setting. See
 322         <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 323         for details. This setting applies to all unit types that support resource control settings, with the exception
 324         of slice units. Defaults to 15%, which equals 4915 with the kernel's defaults on the host, but might be smaller
 325         in OS containers.</para></listitem>
 326       </varlistentry>
 327
 328       <varlistentry>
 329         <term><varname>DefaultLimitCPU=</varname></term>
 330         <term><varname>DefaultLimitFSIZE=</varname></term>
 331         <term><varname>DefaultLimitDATA=</varname></term>
 332         <term><varname>DefaultLimitSTACK=</varname></term>
 333         <term><varname>DefaultLimitCORE=</varname></term>
 334         <term><varname>DefaultLimitRSS=</varname></term>
 335         <term><varname>DefaultLimitNOFILE=</varname></term>
 336         <term><varname>DefaultLimitAS=</varname></term>
 337         <term><varname>DefaultLimitNPROC=</varname></term>
 338         <term><varname>DefaultLimitMEMLOCK=</varname></term>
 339         <term><varname>DefaultLimitLOCKS=</varname></term>
 340         <term><varname>DefaultLimitSIGPENDING=</varname></term>
 341         <term><varname>DefaultLimitMSGQUEUE=</varname></term>
 342         <term><varname>DefaultLimitNICE=</varname></term>
 343         <term><varname>DefaultLimitRTPRIO=</varname></term>
 344         <term><varname>DefaultLimitRTTIME=</varname></term>
 345
 346         <listitem><para>These settings control various default
 347         resource limits for units. See
 348         <citerefentry><refentrytitle>setrlimit</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 349         for details. The resource limit is possible to specify in two formats,
 350         <option>value</option> to set soft and hard limits to the same value,
 351         or <option>soft:hard</option> to set both limits individually (e.g. DefaultLimitAS=4G:16G).
 352         Use the string <varname>infinity</varname> to
 353         configure no limit on a specific resource. The multiplicative
 354         suffixes K (=1024), M (=1024*1024) and so on for G, T, P and E
 355         may be used for resource limits measured in bytes
 356         (e.g. DefaultLimitAS=16G). For the limits referring to time values,
 357         the usual time units ms, s, min, h and so on may be used (see
 358         <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 359         for details). Note that if no time unit is specified for
 360         <varname>DefaultLimitCPU=</varname> the default unit of seconds is
 361         implied, while for <varname>DefaultLimitRTTIME=</varname> the default
 362         unit of microseconds is implied. Also, note that the effective
 363         granularity of the limits might influence their
 364         enforcement. For example, time limits specified for
 365         <varname>DefaultLimitCPU=</varname> will be rounded up implicitly to
 366         multiples of 1s. These  settings may be overridden in individual units
 367         using the corresponding LimitXXX= directives. Note that these resource
 368         limits are only defaults for units, they are not applied to PID 1
 369         itself.</para></listitem>
 370       </varlistentry>
 371
 372       <varlistentry>
 373         <term><varname>DefaultOOMPolicy=</varname></term>
 374
 375         <listitem><para>Configure the default policy for reacting to processes being killed by the Linux
 376         Out-Of-Memory (OOM) killer. This may be used to pick a global default for the per-unit
 377         <varname>OOMPolicy=</varname> setting. See
 378         <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 379         for details. Note that this default is not used for services that have <varname>Delegate=</varname>
 380         turned on.</para></listitem>
 381       </varlistentry>
 382     </variablelist>
 383   </refsect1>
 384
 385   <refsect1>
 386       <title>See Also</title>
 387       <para>
 388         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 389         <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
 390         <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 391         <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 392         <citerefentry project='man-pages'><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
 393         <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 394       </para>
 395   </refsect1>
 396
 397 </refentry>