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
 100         affinity for all forked off processes. Takes a list of CPU indices or ranges separated by either
 101         whitespace or commas. CPU ranges are specified by the lower and upper CPU indices separated by a
 102         dash. This option may be specified more than once, in which case the specified CPU affinity masks are
 103         merged. If the empty string is assigned, the mask is reset, all assignments prior to this will have
 104         no effect. Individual services may override the CPU affinity for their processes with the
 105         <varname>CPUAffinity=</varname> setting in unit files, see
 106         <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem>
 107       </varlistentry>
 108
 109       <varlistentry>
 110         <term><varname>NUMAPolicy=</varname></term>
 111
 112         <listitem><para>Configures the NUMA memory policy for the service manager and the default NUMA memory policy
 113         for all forked off processes. Individual services may override the default policy with the
 114         <varname>NUMAPolicy=</varname> setting in unit files, see
 115         <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem>
 116       </varlistentry>
 117
 118       <varlistentry>
 119         <term><varname>NUMAMask=</varname></term>
 120
 121         <listitem><para>Configures the NUMA node mask that will be associated with the selected NUMA policy. Note that
 122         <option>default</option> and <option>local</option> NUMA policies don't require explicit NUMA node mask and
 123         value of the option can be empty. Similarly to <varname>NUMAPolicy=</varname>, value can be overriden
 124         by individual services in unit files, see
 125         <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem>
 126       </varlistentry>
 127
 128       <varlistentry>
 129         <term><varname>RuntimeWatchdogSec=</varname></term>
 130         <term><varname>ShutdownWatchdogSec=</varname></term>
 131
 132         <listitem><para>Configure the hardware watchdog at runtime and at reboot. Takes a timeout value in seconds (or
 133         in other time units if suffixed with <literal>ms</literal>, <literal>min</literal>, <literal>h</literal>,
 134         <literal>d</literal>, <literal>w</literal>). If <varname>RuntimeWatchdogSec=</varname> is set to a non-zero
 135         value, the watchdog hardware (<filename>/dev/watchdog</filename> or the path specified with
 136         <varname>WatchdogDevice=</varname> or the kernel option <varname>systemd.watchdog-device=</varname>) will be
 137         programmed to automatically reboot the system if it is not contacted within the specified timeout interval. The
 138         system manager will ensure to contact it at least once in half the specified timeout interval. This feature
 139         requires a hardware watchdog device to be present, as it is commonly the case in embedded and server
 140         systems. Not all hardware watchdogs allow configuration of all possible reboot timeout values, in which case
 141         the closest available timeout is picked. <varname>ShutdownWatchdogSec=</varname> may be used to configure the
 142         hardware watchdog when the system is asked to reboot. It works as a safety net to ensure that the reboot takes
 143         place even if a clean reboot attempt times out. Note that the <varname>ShutdownWatchdogSec=</varname> timeout
 144         applies only to the second phase of the reboot, i.e. after all regular services are already terminated, and
 145         after the system and service manager process (PID 1) got replaced by the <filename>systemd-shutdown</filename>
 146         binary, see system <citerefentry><refentrytitle>bootup</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 147         for details. During the first phase of the shutdown operation the system and service manager remains running
 148         and hence <varname>RuntimeWatchdogSec=</varname> is still honoured. In order to define a timeout on this first
 149         phase of system shutdown, configure <varname>JobTimeoutSec=</varname> and <varname>JobTimeoutAction=</varname>
 150         in the <literal>[Unit]</literal> section of the <filename>shutdown.target</filename> unit. By default
 151         <varname>RuntimeWatchdogSec=</varname> defaults to 0 (off), and <varname>ShutdownWatchdogSec=</varname> to
 152         10min. These settings have no effect if a hardware watchdog is not available.</para></listitem>
 153       </varlistentry>
 154
 155       <varlistentry>
 156         <term><varname>WatchdogDevice=</varname></term>
 157
 158         <listitem><para>Configure the hardware watchdog device that the
 159         runtime and shutdown watchdog timers will open and use. Defaults
 160         to <filename>/dev/watchdog</filename>. This setting has no
 161         effect if a hardware watchdog is not available.</para></listitem>
 162       </varlistentry>
 163
 164       <varlistentry>
 165         <term><varname>CapabilityBoundingSet=</varname></term>
 166
 167         <listitem><para>Controls which capabilities to include in the
 168         capability bounding set for PID 1 and its children. See
 169         <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 170         for details. Takes a whitespace-separated list of capability
 171         names as read by
 172         <citerefentry project='mankier'><refentrytitle>cap_from_name</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
 173         Capabilities listed will be included in the bounding set, all
 174         others are removed. If the list of capabilities is prefixed
 175         with ~, all but the listed capabilities will be included, the
 176         effect of the assignment inverted. Note that this option also
 177         affects the respective capabilities in the effective,
 178         permitted and inheritable capability sets. The capability
 179         bounding set may also be individually configured for units
 180         using the <varname>CapabilityBoundingSet=</varname> directive
 181         for units, but note that capabilities dropped for PID 1 cannot
 182         be regained in individual units, they are lost for
 183         good.</para></listitem>
 184       </varlistentry>
 185
 186       <varlistentry>
 187         <term><varname>NoNewPrivileges=</varname></term>
 188
 189         <listitem><para>Takes a boolean argument. If true, ensures that PID 1
 190         and all its children can never gain new privileges through
 191         <citerefentry project='man-pages'><refentrytitle>execve</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 192         (e.g. via setuid or setgid bits, or filesystem capabilities).
 193         Defaults to false. General purpose distributions commonly rely
 194         on executables with setuid or setgid bits and will thus not
 195         function properly with this option enabled. Individual units
 196         cannot disable this option.
 197         Also see <ulink url="https://www.kernel.org/doc/html/latest/userspace-api/no_new_privs.html">No New Privileges Flag</ulink>.
 198         </para></listitem>
 199       </varlistentry>
 200
 201       <varlistentry>
 202         <term><varname>SystemCallArchitectures=</varname></term>
 203
 204         <listitem><para>Takes a space-separated list of architecture
 205         identifiers. Selects from which architectures system calls may
 206         be invoked on this system. This may be used as an effective
 207         way to disable invocation of non-native binaries system-wide,
 208         for example to prohibit execution of 32-bit x86 binaries on
 209         64-bit x86-64 systems. This option operates system-wide, and
 210         acts similar to the
 211         <varname>SystemCallArchitectures=</varname> setting of unit
 212         files, see
 213         <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 214         for details. This setting defaults to the empty list, in which
 215         case no filtering of system calls based on architecture is
 216         applied. Known architecture identifiers are
 217         <literal>x86</literal>, <literal>x86-64</literal>,
 218         <literal>x32</literal>, <literal>arm</literal> and the special
 219         identifier <literal>native</literal>. The latter implicitly
 220         maps to the native architecture of the system (or more
 221         specifically, the architecture the system manager was compiled
 222         for). Set this setting to <literal>native</literal> to
 223         prohibit execution of any non-native binaries. When a binary
 224         executes a system call of an architecture that is not listed
 225         in this setting, it will be immediately terminated with the
 226         SIGSYS signal.</para></listitem>
 227       </varlistentry>
 228
 229       <varlistentry>
 230         <term><varname>TimerSlackNSec=</varname></term>
 231
 232         <listitem><para>Sets the timer slack in nanoseconds for PID 1,
 233         which is inherited by all executed processes, unless
 234         overridden individually, for example with the
 235         <varname>TimerSlackNSec=</varname> setting in service units
 236         (for details see
 237         <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>).
 238         The timer slack controls the accuracy of wake-ups triggered by
 239         system timers. See
 240         <citerefentry><refentrytitle>prctl</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 241         for more information. Note that in contrast to most other time
 242         span definitions this parameter takes an integer value in
 243         nano-seconds if no unit is specified. The usual time units are
 244         understood too.</para></listitem>
 245       </varlistentry>
 246
 247       <varlistentry>
 248         <term><varname>DefaultTimerAccuracySec=</varname></term>
 249
 250         <listitem><para>Sets the default accuracy of timer units. This
 251         controls the global default for the
 252         <varname>AccuracySec=</varname> setting of timer units, see
 253         <citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 254         for details. <varname>AccuracySec=</varname> set in individual
 255         units override the global default for the specific unit.
 256         Defaults to 1min. Note that the accuracy of timer units is
 257         also affected by the configured timer slack for PID 1, see
 258         <varname>TimerSlackNSec=</varname> above.</para></listitem>
 259       </varlistentry>
 260
 261       <varlistentry>
 262         <term><varname>DefaultTimeoutStartSec=</varname></term>
 263         <term><varname>DefaultTimeoutStopSec=</varname></term>
 264         <term><varname>DefaultTimeoutAbortSec=</varname></term>
 265         <term><varname>DefaultRestartSec=</varname></term>
 266
 267         <listitem><para>Configures the default timeouts for starting,
 268         stopping and aborting of units, as well as the default time to sleep
 269         between automatic restarts of units, as configured per-unit in
 270         <varname>TimeoutStartSec=</varname>,
 271         <varname>TimeoutStopSec=</varname>,
 272         <varname>TimeoutAbortSec=</varname> and
 273         <varname>RestartSec=</varname> (for services, see
 274         <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 275         for details on the per-unit settings). Disabled by default, when
 276         service with <varname>Type=oneshot</varname> is used.
 277         For non-service units,
 278         <varname>DefaultTimeoutStartSec=</varname> sets the default
 279         <varname>TimeoutSec=</varname>
 280         value. <varname>DefaultTimeoutStartSec=</varname> and
 281         <varname>DefaultTimeoutStopSec=</varname> default to
 282         90s. <varname>DefaultTimeoutAbortSec=</varname> is not set by default
 283         so that all units fall back to <varname>TimeoutStopSec=</varname>.
 284         <varname>DefaultRestartSec=</varname> defaults to
 285         100ms.</para></listitem>
 286       </varlistentry>
 287
 288       <varlistentry>
 289         <term><varname>DefaultStartLimitIntervalSec=</varname></term>
 290         <term><varname>DefaultStartLimitBurst=</varname></term>
 291
 292         <listitem><para>Configure the default unit start rate
 293         limiting, as configured per-service by
 294         <varname>StartLimitIntervalSec=</varname> and
 295         <varname>StartLimitBurst=</varname>. See
 296         <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 297         for details on the per-service settings.
 298         <varname>DefaultStartLimitIntervalSec=</varname> defaults to
 299         10s. <varname>DefaultStartLimitBurst=</varname> defaults to
 300         5.</para></listitem>
 301       </varlistentry>
 302
 303       <varlistentry>
 304         <term><varname>DefaultEnvironment=</varname></term>
 305
 306         <listitem><para>Sets manager environment variables passed to
 307         all executed processes. Takes a space-separated list of
 308         variable assignments. See
 309         <citerefentry project='man-pages'><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 310         for details about environment variables.</para>
 311
 312         <para>Example:
 313
 314         <programlisting>DefaultEnvironment="VAR1=word1 word2" VAR2=word3 "VAR3=word 5 6"</programlisting>
 315
 316         Sets three variables
 317         <literal>VAR1</literal>,
 318         <literal>VAR2</literal>,
 319         <literal>VAR3</literal>.</para></listitem>
 320       </varlistentry>
 321
 322       <varlistentry>
 323         <term><varname>DefaultCPUAccounting=</varname></term>
 324         <term><varname>DefaultBlockIOAccounting=</varname></term>
 325         <term><varname>DefaultMemoryAccounting=</varname></term>
 326         <term><varname>DefaultTasksAccounting=</varname></term>
 327         <term><varname>DefaultIOAccounting=</varname></term>
 328         <term><varname>DefaultIPAccounting=</varname></term>
 329
 330         <listitem><para>Configure the default resource accounting settings, as configured per-unit by
 331         <varname>CPUAccounting=</varname>, <varname>BlockIOAccounting=</varname>, <varname>MemoryAccounting=</varname>,
 332         <varname>TasksAccounting=</varname>, <varname>IOAccounting=</varname> and <varname>IPAccounting=</varname>. See
 333         <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 334         for details on the per-unit settings. <varname>DefaultTasksAccounting=</varname> defaults to yes,
 335         <varname>DefaultMemoryAccounting=</varname> to &MEMORY_ACCOUNTING_DEFAULT;. <varname>DefaultCPUAccounting=</varname>
 336         defaults to yes if enabling CPU accounting doesn't require the CPU controller to be enabled (Linux 4.15+ using the
 337         unified hierarchy for resource control), otherwise it defaults to no. The other three settings default to no.</para></listitem>
 338       </varlistentry>
 339
 340       <varlistentry>
 341         <term><varname>DefaultTasksMax=</varname></term>
 342
 343         <listitem><para>Configure the default value for the per-unit <varname>TasksMax=</varname> setting. See
 344         <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 345         for details. This setting applies to all unit types that support resource control settings, with the exception
 346         of slice units. Defaults to 15%, which equals 4915 with the kernel's defaults on the host, but might be smaller
 347         in OS containers.</para></listitem>
 348       </varlistentry>
 349
 350       <varlistentry>
 351         <term><varname>DefaultLimitCPU=</varname></term>
 352         <term><varname>DefaultLimitFSIZE=</varname></term>
 353         <term><varname>DefaultLimitDATA=</varname></term>
 354         <term><varname>DefaultLimitSTACK=</varname></term>
 355         <term><varname>DefaultLimitCORE=</varname></term>
 356         <term><varname>DefaultLimitRSS=</varname></term>
 357         <term><varname>DefaultLimitNOFILE=</varname></term>
 358         <term><varname>DefaultLimitAS=</varname></term>
 359         <term><varname>DefaultLimitNPROC=</varname></term>
 360         <term><varname>DefaultLimitMEMLOCK=</varname></term>
 361         <term><varname>DefaultLimitLOCKS=</varname></term>
 362         <term><varname>DefaultLimitSIGPENDING=</varname></term>
 363         <term><varname>DefaultLimitMSGQUEUE=</varname></term>
 364         <term><varname>DefaultLimitNICE=</varname></term>
 365         <term><varname>DefaultLimitRTPRIO=</varname></term>
 366         <term><varname>DefaultLimitRTTIME=</varname></term>
 367
 368         <listitem><para>These settings control various default
 369         resource limits for units. See
 370         <citerefentry><refentrytitle>setrlimit</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 371         for details. The resource limit is possible to specify in two formats,
 372         <option>value</option> to set soft and hard limits to the same value,
 373         or <option>soft:hard</option> to set both limits individually (e.g. DefaultLimitAS=4G:16G).
 374         Use the string <varname>infinity</varname> to
 375         configure no limit on a specific resource. The multiplicative
 376         suffixes K (=1024), M (=1024*1024) and so on for G, T, P and E
 377         may be used for resource limits measured in bytes
 378         (e.g. DefaultLimitAS=16G). For the limits referring to time values,
 379         the usual time units ms, s, min, h and so on may be used (see
 380         <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 381         for details). Note that if no time unit is specified for
 382         <varname>DefaultLimitCPU=</varname> the default unit of seconds is
 383         implied, while for <varname>DefaultLimitRTTIME=</varname> the default
 384         unit of microseconds is implied. Also, note that the effective
 385         granularity of the limits might influence their
 386         enforcement. For example, time limits specified for
 387         <varname>DefaultLimitCPU=</varname> will be rounded up implicitly to
 388         multiples of 1s. These  settings may be overridden in individual units
 389         using the corresponding LimitXXX= directives. Note that these resource
 390         limits are only defaults for units, they are not applied to PID 1
 391         itself.</para></listitem>
 392       </varlistentry>
 393
 394       <varlistentry>
 395         <term><varname>DefaultOOMPolicy=</varname></term>
 396
 397         <listitem><para>Configure the default policy for reacting to processes being killed by the Linux
 398         Out-Of-Memory (OOM) killer. This may be used to pick a global default for the per-unit
 399         <varname>OOMPolicy=</varname> setting. See
 400         <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 401         for details. Note that this default is not used for services that have <varname>Delegate=</varname>
 402         turned on.</para></listitem>
 403       </varlistentry>
 404     </variablelist>
 405   </refsect1>
 406
 407   <refsect1>
 408       <title>See Also</title>
 409       <para>
 410         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 411         <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
 412         <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 413         <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 414         <citerefentry project='man-pages'><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
 415         <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 416       </para>
 417   </refsect1>
 418
 419 </refentry>