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>7</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     [Manager] section:</para>
  62
  63     <variablelist class='config-directives'>
  64
  65       <varlistentry>
  66         <term><varname>LogColor=</varname></term>
  67         <term><varname>LogLevel=</varname></term>
  68         <term><varname>LogLocation=</varname></term>
  69         <term><varname>LogTarget=</varname></term>
  70         <term><varname>LogTime=</varname></term>
  71         <term><varname>DumpCore=yes</varname></term>
  72         <term><varname>CrashChangeVT=no</varname></term>
  73         <term><varname>CrashShell=no</varname></term>
  74         <term><varname>CrashReboot=no</varname></term>
  75         <term><varname>ShowStatus=yes</varname></term>
  76         <term><varname>DefaultStandardOutput=journal</varname></term>
  77         <term><varname>DefaultStandardError=inherit</varname></term>
  78
  79         <listitem><para>Configures various parameters of basic manager operation. These options may be overridden by
  80         the respective process and kernel command line arguments. See
  81         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry> for
  82         details.</para></listitem>
  83       </varlistentry>
  84
  85       <varlistentry>
  86         <term><varname>CtrlAltDelBurstAction=</varname></term>
  87
  88         <listitem><para>Defines what action will be performed
  89         if user presses Ctrl-Alt-Delete more than 7 times in 2s.
  90         Can be set to <literal>reboot-force</literal>, <literal>poweroff-force</literal>,
  91         <literal>reboot-immediate</literal>, <literal>poweroff-immediate</literal>
  92         or disabled with <literal>none</literal>. Defaults to
  93         <literal>reboot-force</literal>.
  94         </para></listitem>
  95       </varlistentry>
  96
  97       <varlistentry>
  98         <term><varname>CPUAffinity=</varname></term>
  99
 100         <listitem><para>Configures the CPU affinity for the service manager as well as the default CPU
 101         affinity for all forked off processes. Takes a list of CPU indices or ranges separated by either
 102         whitespace or commas. CPU ranges are specified by the lower and upper CPU indices separated by a
 103         dash. This option may be specified more than once, in which case the specified CPU affinity masks are
 104         merged. If the empty string is assigned, the mask is reset, all assignments prior to this will have
 105         no effect. Individual services may override the CPU affinity for their processes with the
 106         <varname>CPUAffinity=</varname> setting in unit files, see
 107         <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem>
 108       </varlistentry>
 109
 110       <varlistentry>
 111         <term><varname>NUMAPolicy=</varname></term>
 112
 113         <listitem><para>Configures the NUMA memory policy for the service manager and the default NUMA memory policy
 114         for all forked off processes. Individual services may override the default policy with the
 115         <varname>NUMAPolicy=</varname> setting in unit files, see
 116         <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem>
 117       </varlistentry>
 118
 119       <varlistentry>
 120         <term><varname>NUMAMask=</varname></term>
 121
 122         <listitem><para>Configures the NUMA node mask that will be associated with the selected NUMA policy. Note that
 123         <option>default</option> and <option>local</option> NUMA policies don't require explicit NUMA node mask and
 124         value of the option can be empty. Similarly to <varname>NUMAPolicy=</varname>, value can be overridden
 125         by individual services in unit files, see
 126         <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem>
 127       </varlistentry>
 128
 129       <varlistentry>
 130         <term><varname>RuntimeWatchdogSec=</varname></term>
 131         <term><varname>RebootWatchdogSec=</varname></term>
 132         <term><varname>KExecWatchdogSec=</varname></term>
 133
 134         <listitem><para>Configure the hardware watchdog at runtime and at reboot. Takes a timeout value in seconds (or
 135         in other time units if suffixed with <literal>ms</literal>, <literal>min</literal>, <literal>h</literal>,
 136         <literal>d</literal>, <literal>w</literal>). If <varname>RuntimeWatchdogSec=</varname> is set to a non-zero
 137         value, the watchdog hardware (<filename>/dev/watchdog</filename> or the path specified with
 138         <varname>WatchdogDevice=</varname> or the kernel option <varname>systemd.watchdog-device=</varname>) will be
 139         programmed to automatically reboot the system if it is not contacted within the specified timeout interval. The
 140         system manager will ensure to contact it at least once in half the specified timeout interval. This feature
 141         requires a hardware watchdog device to be present, as it is commonly the case in embedded and server
 142         systems. Not all hardware watchdogs allow configuration of all possible reboot timeout values, in which case
 143         the closest available timeout is picked. <varname>RebootWatchdogSec=</varname> may be used to configure the
 144         hardware watchdog when the system is asked to reboot. It works as a safety net to ensure that the reboot takes
 145         place even if a clean reboot attempt times out. Note that the <varname>RebootWatchdogSec=</varname> timeout
 146         applies only to the second phase of the reboot, i.e. after all regular services are already terminated, and
 147         after the system and service manager process (PID 1) got replaced by the <filename>systemd-shutdown</filename>
 148         binary, see system <citerefentry><refentrytitle>bootup</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 149         for details. During the first phase of the shutdown operation the system and service manager remains running
 150         and hence <varname>RuntimeWatchdogSec=</varname> is still honoured. In order to define a timeout on this first
 151         phase of system shutdown, configure <varname>JobTimeoutSec=</varname> and <varname>JobTimeoutAction=</varname>
 152         in the [Unit] section of the <filename>shutdown.target</filename> unit. By default
 153         <varname>RuntimeWatchdogSec=</varname> defaults to 0 (off), and <varname>RebootWatchdogSec=</varname> to
 154         10min. <varname>KExecWatchdogSec=</varname> may be used to additionally enable the watchdog when kexec
 155         is being executed rather than when rebooting. Note that if the kernel does not reset the watchdog on kexec (depending
 156         on the specific hardware and/or driver), in this case the watchdog might not get disabled after kexec succeeds
 157         and thus the system might get rebooted, unless <varname>RuntimeWatchdogSec=</varname> is also enabled at the same time.
 158         For this reason it is recommended to enable <varname>KExecWatchdogSec=</varname> only if
 159         <varname>RuntimeWatchdogSec=</varname> is also enabled.
 160         These settings have no effect if a hardware watchdog is not available.</para></listitem>
 161       </varlistentry>
 162
 163       <varlistentry>
 164         <term><varname>WatchdogDevice=</varname></term>
 165
 166         <listitem><para>Configure the hardware watchdog device that the
 167         runtime and shutdown watchdog timers will open and use. Defaults
 168         to <filename>/dev/watchdog</filename>. This setting has no
 169         effect if a hardware watchdog is not available.</para></listitem>
 170       </varlistentry>
 171
 172       <varlistentry>
 173         <term><varname>CapabilityBoundingSet=</varname></term>
 174
 175         <listitem><para>Controls which capabilities to include in the
 176         capability bounding set for PID 1 and its children. See
 177         <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 178         for details. Takes a whitespace-separated list of capability
 179         names as read by
 180         <citerefentry project='mankier'><refentrytitle>cap_from_name</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
 181         Capabilities listed will be included in the bounding set, all
 182         others are removed. If the list of capabilities is prefixed
 183         with ~, all but the listed capabilities will be included, the
 184         effect of the assignment inverted. Note that this option also
 185         affects the respective capabilities in the effective,
 186         permitted and inheritable capability sets. The capability
 187         bounding set may also be individually configured for units
 188         using the <varname>CapabilityBoundingSet=</varname> directive
 189         for units, but note that capabilities dropped for PID 1 cannot
 190         be regained in individual units, they are lost for
 191         good.</para></listitem>
 192       </varlistentry>
 193
 194       <varlistentry>
 195         <term><varname>NoNewPrivileges=</varname></term>
 196
 197         <listitem><para>Takes a boolean argument. If true, ensures that PID 1
 198         and all its children can never gain new privileges through
 199         <citerefentry project='man-pages'><refentrytitle>execve</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 200         (e.g. via setuid or setgid bits, or filesystem capabilities).
 201         Defaults to false. General purpose distributions commonly rely
 202         on executables with setuid or setgid bits and will thus not
 203         function properly with this option enabled. Individual units
 204         cannot disable this option.
 205         Also see <ulink url="https://www.kernel.org/doc/html/latest/userspace-api/no_new_privs.html">No New Privileges Flag</ulink>.
 206         </para></listitem>
 207       </varlistentry>
 208
 209       <varlistentry>
 210         <term><varname>SystemCallArchitectures=</varname></term>
 211
 212         <listitem><para>Takes a space-separated list of architecture
 213         identifiers. Selects from which architectures system calls may
 214         be invoked on this system. This may be used as an effective
 215         way to disable invocation of non-native binaries system-wide,
 216         for example to prohibit execution of 32-bit x86 binaries on
 217         64-bit x86-64 systems. This option operates system-wide, and
 218         acts similar to the
 219         <varname>SystemCallArchitectures=</varname> setting of unit
 220         files, see
 221         <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 222         for details. This setting defaults to the empty list, in which
 223         case no filtering of system calls based on architecture is
 224         applied. Known architecture identifiers are
 225         <literal>x86</literal>, <literal>x86-64</literal>,
 226         <literal>x32</literal>, <literal>arm</literal> and the special
 227         identifier <literal>native</literal>. The latter implicitly
 228         maps to the native architecture of the system (or more
 229         specifically, the architecture the system manager was compiled
 230         for). Set this setting to <literal>native</literal> to
 231         prohibit execution of any non-native binaries. When a binary
 232         executes a system call of an architecture that is not listed
 233         in this setting, it will be immediately terminated with the
 234         SIGSYS signal.</para></listitem>
 235       </varlistentry>
 236
 237       <varlistentry>
 238         <term><varname>TimerSlackNSec=</varname></term>
 239
 240         <listitem><para>Sets the timer slack in nanoseconds for PID 1,
 241         which is inherited by all executed processes, unless
 242         overridden individually, for example with the
 243         <varname>TimerSlackNSec=</varname> setting in service units
 244         (for details see
 245         <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>).
 246         The timer slack controls the accuracy of wake-ups triggered by
 247         system timers. See
 248         <citerefentry><refentrytitle>prctl</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 249         for more information. Note that in contrast to most other time
 250         span definitions this parameter takes an integer value in
 251         nano-seconds if no unit is specified. The usual time units are
 252         understood too.</para></listitem>
 253       </varlistentry>
 254
 255       <varlistentry>
 256         <term><varname>StatusUnitFormat=</varname></term>
 257
 258         <listitem><para>Takes either <option>name</option> or <option>description</option> as the value. If
 259         <option>name</option>, the system manager will use unit names in status messages, instead of the
 260         longer and more informative descriptions set with <varname>Description=</varname>, see
 261         <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
 262         </para></listitem>
 263       </varlistentry>
 264
 265       <varlistentry>
 266         <term><varname>DefaultTimerAccuracySec=</varname></term>
 267
 268         <listitem><para>Sets the default accuracy of timer units. This
 269         controls the global default for the
 270         <varname>AccuracySec=</varname> setting of timer units, see
 271         <citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 272         for details. <varname>AccuracySec=</varname> set in individual
 273         units override the global default for the specific unit.
 274         Defaults to 1min. Note that the accuracy of timer units is
 275         also affected by the configured timer slack for PID 1, see
 276         <varname>TimerSlackNSec=</varname> above.</para></listitem>
 277       </varlistentry>
 278
 279       <varlistentry>
 280         <term><varname>DefaultTimeoutStartSec=</varname></term>
 281         <term><varname>DefaultTimeoutStopSec=</varname></term>
 282         <term><varname>DefaultTimeoutAbortSec=</varname></term>
 283         <term><varname>DefaultRestartSec=</varname></term>
 284
 285         <listitem><para>Configures the default timeouts for starting,
 286         stopping and aborting of units, as well as the default time to sleep
 287         between automatic restarts of units, as configured per-unit in
 288         <varname>TimeoutStartSec=</varname>,
 289         <varname>TimeoutStopSec=</varname>,
 290         <varname>TimeoutAbortSec=</varname> and
 291         <varname>RestartSec=</varname> (for services, see
 292         <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 293         for details on the per-unit settings). Disabled by default, when
 294         service with <varname>Type=oneshot</varname> is used.
 295         For non-service units,
 296         <varname>DefaultTimeoutStartSec=</varname> sets the default
 297         <varname>TimeoutSec=</varname>
 298         value. <varname>DefaultTimeoutStartSec=</varname> and
 299         <varname>DefaultTimeoutStopSec=</varname> default to
 300         90s. <varname>DefaultTimeoutAbortSec=</varname> is not set by default
 301         so that all units fall back to <varname>TimeoutStopSec=</varname>.
 302         <varname>DefaultRestartSec=</varname> defaults to
 303         100ms.</para></listitem>
 304       </varlistentry>
 305
 306       <varlistentry>
 307         <term><varname>DefaultStartLimitIntervalSec=</varname></term>
 308         <term><varname>DefaultStartLimitBurst=</varname></term>
 309
 310         <listitem><para>Configure the default unit start rate
 311         limiting, as configured per-service by
 312         <varname>StartLimitIntervalSec=</varname> and
 313         <varname>StartLimitBurst=</varname>. See
 314         <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 315         for details on the per-service settings.
 316         <varname>DefaultStartLimitIntervalSec=</varname> defaults to
 317         10s. <varname>DefaultStartLimitBurst=</varname> defaults to
 318         5.</para></listitem>
 319       </varlistentry>
 320
 321       <varlistentry>
 322         <term><varname>DefaultEnvironment=</varname></term>
 323
 324         <listitem><para>Sets manager environment variables passed to
 325         all executed processes. Takes a space-separated list of
 326         variable assignments. See
 327         <citerefentry project='man-pages'><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 328         for details about environment variables.</para>
 329
 330         <para>Example:
 331
 332         <programlisting>DefaultEnvironment="VAR1=word1 word2" VAR2=word3 "VAR3=word 5 6"</programlisting>
 333
 334         Sets three variables
 335         <literal>VAR1</literal>,
 336         <literal>VAR2</literal>,
 337         <literal>VAR3</literal>.</para></listitem>
 338       </varlistentry>
 339
 340       <varlistentry>
 341         <term><varname>DefaultCPUAccounting=</varname></term>
 342         <term><varname>DefaultBlockIOAccounting=</varname></term>
 343         <term><varname>DefaultMemoryAccounting=</varname></term>
 344         <term><varname>DefaultTasksAccounting=</varname></term>
 345         <term><varname>DefaultIOAccounting=</varname></term>
 346         <term><varname>DefaultIPAccounting=</varname></term>
 347
 348         <listitem><para>Configure the default resource accounting settings, as configured per-unit by
 349         <varname>CPUAccounting=</varname>, <varname>BlockIOAccounting=</varname>, <varname>MemoryAccounting=</varname>,
 350         <varname>TasksAccounting=</varname>, <varname>IOAccounting=</varname> and <varname>IPAccounting=</varname>. See
 351         <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 352         for details on the per-unit settings. <varname>DefaultTasksAccounting=</varname> defaults to yes,
 353         <varname>DefaultMemoryAccounting=</varname> to &MEMORY_ACCOUNTING_DEFAULT;. <varname>DefaultCPUAccounting=</varname>
 354         defaults to yes if enabling CPU accounting doesn't require the CPU controller to be enabled (Linux 4.15+ using the
 355         unified hierarchy for resource control), otherwise it defaults to no. The other three settings default to no.</para></listitem>
 356       </varlistentry>
 357
 358       <varlistentry>
 359         <term><varname>DefaultTasksMax=</varname></term>
 360
 361         <listitem><para>Configure the default value for the per-unit <varname>TasksMax=</varname> setting. See
 362         <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 363         for details. This setting applies to all unit types that support resource control settings, with the exception
 364         of slice units. Defaults to 15%, which equals 4915 with the kernel's defaults on the host, but might be smaller
 365         in OS containers.</para></listitem>
 366       </varlistentry>
 367
 368       <varlistentry>
 369         <term><varname>DefaultLimitCPU=</varname></term>
 370         <term><varname>DefaultLimitFSIZE=</varname></term>
 371         <term><varname>DefaultLimitDATA=</varname></term>
 372         <term><varname>DefaultLimitSTACK=</varname></term>
 373         <term><varname>DefaultLimitCORE=</varname></term>
 374         <term><varname>DefaultLimitRSS=</varname></term>
 375         <term><varname>DefaultLimitNOFILE=</varname></term>
 376         <term><varname>DefaultLimitAS=</varname></term>
 377         <term><varname>DefaultLimitNPROC=</varname></term>
 378         <term><varname>DefaultLimitMEMLOCK=</varname></term>
 379         <term><varname>DefaultLimitLOCKS=</varname></term>
 380         <term><varname>DefaultLimitSIGPENDING=</varname></term>
 381         <term><varname>DefaultLimitMSGQUEUE=</varname></term>
 382         <term><varname>DefaultLimitNICE=</varname></term>
 383         <term><varname>DefaultLimitRTPRIO=</varname></term>
 384         <term><varname>DefaultLimitRTTIME=</varname></term>
 385
 386         <listitem><para>These settings control various default resource limits for processes executed by
 387         units. See
 388         <citerefentry><refentrytitle>setrlimit</refentrytitle><manvolnum>2</manvolnum></citerefentry> for
 389         details. These settings may be overridden in individual units using the corresponding
 390         <varname>LimitXXX=</varname> directives and they accept the same parameter syntax,
 391         see <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 392         for details. Note that these resource limits are only defaults
 393         for units, they are not applied to the service manager process (i.e. PID 1) itself.</para></listitem>
 394       </varlistentry>
 395
 396       <varlistentry>
 397         <term><varname>DefaultOOMPolicy=</varname></term>
 398
 399         <listitem><para>Configure the default policy for reacting to processes being killed by the Linux
 400         Out-Of-Memory (OOM) killer. This may be used to pick a global default for the per-unit
 401         <varname>OOMPolicy=</varname> setting. See
 402         <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 403         for details. Note that this default is not used for services that have <varname>Delegate=</varname>
 404         turned on.</para></listitem>
 405       </varlistentry>
 406     </variablelist>
 407   </refsect1>
 408
 409   <refsect1>
 410       <title>See Also</title>
 411       <para>
 412         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 413         <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
 414         <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 415         <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
 416         <citerefentry project='man-pages'><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
 417         <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry>
 418       </para>
 419   </refsect1>
 420
 421 </refentry>