NAME | SYNOPSIS | DESCRIPTION | CONFIGURATION DIRECTORIES AND PRECEDENCE | OPTIONS | SEE ALSO | COLOPHON

SYSTEMD-SYSTEM.CONF(5)       systemd-system.conf      SYSTEMD-SYSTEM.CONF(5)

NAME         top

       systemd-system.conf, system.conf.d, systemd-user.conf, user.conf.d -
       System and session service manager configuration files

SYNOPSIS         top

       /etc/systemd/system.conf, /etc/systemd/system.conf.d/*.conf,
       /run/systemd/system.conf.d/*.conf,
       /usr/lib/systemd/system.conf.d/*.conf

       /etc/systemd/user.conf, /etc/systemd/user.conf.d/*.conf,
       /run/systemd/user.conf.d/*.conf, /usr/lib/systemd/user.conf.d/*.conf

DESCRIPTION         top

       When run as a system instance, systemd interprets the configuration
       file system.conf and the files in system.conf.d directories; when run
       as a user instance, systemd interprets the configuration file
       user.conf and the files in user.conf.d directories. These
       configuration files contain a few settings controlling basic manager
       operations.

CONFIGURATION DIRECTORIES AND PRECEDENCE         top

       The default configuration is defined during compilation, so a
       configuration file is only needed when it is necessary to deviate
       from those defaults. By default, the configuration file in
       /etc/systemd/ contains commented out entries showing the defaults as
       a guide to the administrator. This file can be edited to create local
       overrides.

       When packages need to customize the configuration, they can install
       configuration snippets in /usr/lib/systemd/*.conf.d/. Files in /etc/
       are reserved for the local administrator, who may use this logic to
       override the configuration files installed by vendor packages. The
       main configuration file is read before any of the configuration
       directories, and has the lowest precedence; entries in a file in any
       configuration directory override entries in the single configuration
       file. Files in the *.conf.d/ configuration subdirectories are sorted
       by their filename in lexicographic order, regardless of which of the
       subdirectories they reside in. If multiple files specify the same
       option, the entry in the file with the lexicographically latest name
       takes precedence. It is recommended to prefix all filenames in those
       subdirectories with a two-digit number and a dash, to simplify the
       ordering of the files.

       To disable a configuration file supplied by the vendor, the
       recommended way is to place a symlink to /dev/null in the
       configuration directory in /etc/, with the same filename as the
       vendor configuration file.

OPTIONS         top

       All options are configured in the "[Manager]" section:

       LogLevel=, LogTarget=, LogColor=, LogLocation=, DumpCore=yes,
       CrashChangeVT=no, CrashShell=no, CrashReboot=no, ShowStatus=yes,
       DefaultStandardOutput=journal, DefaultStandardError=inherit
           Configures various parameters of basic manager operation. These
           options may be overridden by the respective process and kernel
           command line arguments. See systemd(1) for details.

       CtrlAltDelBurstAction=
           Defines what action will be performed if user presses
           Ctrl-Alt-Delete more than 7 times in 2s. Can be set to
           "reboot-force", "poweroff-force", "reboot-immediate",
           "poweroff-immediate" or disabled with "none". Defaults to
           "reboot-force".

       CPUAffinity=
           Configures the initial CPU affinity for the init process. Takes a
           list of CPU indices or ranges separated by either whitespace or
           commas. CPU ranges are specified by the lower and upper CPU
           indices separated by a dash.

       JoinControllers=cpu,cpuacct net_cls,netprio
           Configures controllers that shall be mounted in a single
           hierarchy. By default, systemd will mount all controllers which
           are enabled in the kernel in individual hierarchies, with the
           exception of those listed in this setting. Takes a
           space-separated list of comma-separated controller names, in
           order to allow multiple joined hierarchies. Defaults to
           'cpu,cpuacct'. Pass an empty string to ensure that systemd mounts
           all controllers in separate hierarchies.

           Note that this option is only applied once, at very early boot.
           If you use an initial RAM disk (initrd) that uses systemd, it
           might hence be necessary to rebuild the initrd if this option is
           changed, and make sure the new configuration file is included in
           it. Otherwise, the initrd might mount the controller hierarchies
           in a different configuration than intended, and the main system
           cannot remount them anymore.

       RuntimeWatchdogSec=, ShutdownWatchdogSec=
           Configure the hardware watchdog at runtime and at reboot. Takes a
           timeout value in seconds (or in other time units if suffixed with
           "ms", "min", "h", "d", "w"). If RuntimeWatchdogSec= is set to a
           non-zero value, the watchdog hardware (/dev/watchdog) will be
           programmed to automatically reboot the system if it is not
           contacted within the specified timeout interval. The system
           manager will ensure to contact it at least once in half the
           specified timeout interval. This feature requires a hardware
           watchdog device to be present, as it is commonly the case in
           embedded and server systems. Not all hardware watchdogs allow
           configuration of the reboot timeout, in which case the closest
           available timeout is picked.  ShutdownWatchdogSec= may be used to
           configure the hardware watchdog when the system is asked to
           reboot. It works as a safety net to ensure that the reboot takes
           place even if a clean reboot attempt times out. By default
           RuntimeWatchdogSec= defaults to 0 (off), and ShutdownWatchdogSec=
           to 10min. These settings have no effect if a hardware watchdog is
           not available.

       CapabilityBoundingSet=
           Controls which capabilities to include in the capability bounding
           set for PID 1 and its children. See capabilities(7) for details.
           Takes a whitespace-separated list of capability names as read by
           cap_from_name(3). Capabilities listed will be included in the
           bounding set, all others are removed. If the list of capabilities
           is prefixed with ~, all but the listed capabilities will be
           included, the effect of the assignment inverted. Note that this
           option also affects the respective capabilities in the effective,
           permitted and inheritable capability sets. The capability
           bounding set may also be individually configured for units using
           the CapabilityBoundingSet= directive for units, but note that
           capabilities dropped for PID 1 cannot be regained in individual
           units, they are lost for good.

       SystemCallArchitectures=
           Takes a space-separated list of architecture identifiers. Selects
           from which architectures system calls may be invoked on this
           system. This may be used as an effective way to disable
           invocation of non-native binaries system-wide, for example to
           prohibit execution of 32-bit x86 binaries on 64-bit x86-64
           systems. This option operates system-wide, and acts similar to
           the SystemCallArchitectures= setting of unit files, see
           systemd.exec(5) for details. This setting defaults to the empty
           list, in which case no filtering of system calls based on
           architecture is applied. Known architecture identifiers are
           "x86", "x86-64", "x32", "arm" and the special identifier
           "native". The latter implicitly maps to the native architecture
           of the system (or more specifically, the architecture the system
           manager was compiled for). Set this setting to "native" to
           prohibit execution of any non-native binaries. When a binary
           executes a system call of an architecture that is not listed in
           this setting, it will be immediately terminated with the SIGSYS
           signal.

       TimerSlackNSec=
           Sets the timer slack in nanoseconds for PID 1, which is inherited
           by all executed processes, unless overridden individually, for
           example with the TimerSlackNSec= setting in service units (for
           details see systemd.exec(5)). The timer slack controls the
           accuracy of wake-ups triggered by system timers. See prctl(2) for
           more information. Note that in contrast to most other time span
           definitions this parameter takes an integer value in nano-seconds
           if no unit is specified. The usual time units are understood too.

       DefaultTimerAccuracySec=
           Sets the default accuracy of timer units. This controls the
           global default for the AccuracySec= setting of timer units, see
           systemd.timer(5) for details.  AccuracySec= set in individual
           units override the global default for the specific unit. Defaults
           to 1min. Note that the accuracy of timer units is also affected
           by the configured timer slack for PID 1, see TimerSlackNSec=
           above.

       DefaultTimeoutStartSec=, DefaultTimeoutStopSec=, DefaultRestartSec=
           Configures the default timeouts for starting and stopping of
           units, as well as the default time to sleep between automatic
           restarts of units, as configured per-unit in TimeoutStartSec=,
           TimeoutStopSec= and RestartSec= (for services, see
           systemd.service(5) for details on the per-unit settings). For
           non-service units, DefaultTimeoutStartSec= sets the default
           TimeoutSec= value.  DefaultTimeoutStartSec= and
           DefaultTimeoutStopSec= default to 90s.  DefaultRestartSec=
           defaults to 100ms.

       DefaultStartLimitIntervalSec=, DefaultStartLimitBurst=
           Configure the default unit start rate limiting, as configured
           per-service by StartLimitIntervalSec= and StartLimitBurst=. See
           systemd.service(5) for details on the per-service settings.
           DefaultStartLimitIntervalSec= defaults to 10s.
           DefaultStartLimitBurst= defaults to 5.

       DefaultEnvironment=
           Sets manager environment variables passed to all executed
           processes. Takes a space-separated list of variable assignments.
           See environ(7) for details about environment variables.

           Example:

               DefaultEnvironment="VAR1=word1 word2" VAR2=word3 "VAR3=word 5 6"

           Sets three variables "VAR1", "VAR2", "VAR3".

       DefaultCPUAccounting=, DefaultBlockIOAccounting=,
       DefaultMemoryAccounting=, DefaultTasksAccounting=
           Configure the default resource accounting settings, as configured
           per-unit by CPUAccounting=, BlockIOAccounting=, MemoryAccounting=
           and TasksAccounting=. See systemd.resource-control(5) for details
           on the per-unit settings.  DefaultTasksAccounting= defaults to
           on, the other three settings to off.

       DefaultTasksMax=
           Configure the default value for the per-unit TasksMax= setting.
           See systemd.resource-control(5) for details. This setting applies
           to all unit types that support resource control settings, with
           the exception of slice units. Defaults to 15%, which equals 4915
           with the kernel's defaults on the host, but might be smaller in
           OS containers.

       DefaultLimitCPU=, DefaultLimitFSIZE=, DefaultLimitDATA=,
       DefaultLimitSTACK=, DefaultLimitCORE=, DefaultLimitRSS=,
       DefaultLimitNOFILE=, DefaultLimitAS=, DefaultLimitNPROC=,
       DefaultLimitMEMLOCK=, DefaultLimitLOCKS=, DefaultLimitSIGPENDING=,
       DefaultLimitMSGQUEUE=, DefaultLimitNICE=, DefaultLimitRTPRIO=,
       DefaultLimitRTTIME=
           These settings control various default resource limits for units.
           See setrlimit(2) for details. The resource limit is possible to
           specify in two formats, value to set soft and hard limits to the
           same value, or soft:hard to set both limits individually (e.g.
           DefaultLimitAS=4G:16G). Use the string infinity to configure no
           limit on a specific resource. The multiplicative suffixes K
           (=1024), M (=1024*1024) and so on for G, T, P and E may be used
           for resource limits measured in bytes (e.g. DefaultLimitAS=16G).
           For the limits referring to time values, the usual time units ms,
           s, min, h and so on may be used (see systemd.time(7) for
           details). Note that if no time unit is specified for
           DefaultLimitCPU= the default unit of seconds is implied, while
           for DefaultLimitRTTIME= the default unit of microseconds is
           implied. Also, note that the effective granularity of the limits
           might influence their enforcement. For example, time limits
           specified for DefaultLimitCPU= will be rounded up implicitly to
           multiples of 1s. These settings may be overridden in individual
           units using the corresponding LimitXXX= directives. Note that
           these resource limits are only defaults for units, they are not
           applied to PID 1 itself.

SEE ALSO         top

       systemd(1), systemd.directives(7), systemd.exec(5),
       systemd.service(5), environ(7), capabilities(7)

COLOPHON         top

       This page is part of the systemd (systemd system and service manager)
       project.  Information about the project can be found at 
       ⟨http://www.freedesktop.org/wiki/Software/systemd⟩.  If you have a bug
       report for this manual page, see 
       ⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩.  This
       page was obtained from the project's upstream Git repository 
       ⟨https://github.com/systemd/systemd.git⟩ on 2017-09-15.  If you dis‐
       cover any rendering problems in this HTML version of the page, or you
       believe there is a better or more up-to-date source for the page, or
       you have corrections or improvements to the information in this
       COLOPHON (which is not part of the original manual page), send a mail
       to man-pages@man7.org

systemd 234                                           SYSTEMD-SYSTEM.CONF(5)

Pages that refer to this page: systemctl(1)systemd(1)journald.conf(5)logind.conf(5)systemd.exec(5)systemd.resource-control(5)systemd.service(5)systemd.socket(5)systemd.swap(5)systemd.timer(5)kernel-command-line(7)systemd.directives(7)systemd.index(7)