SYSTEMD-SYSTEM.CONF(5) systemd-system.conf SYSTEMD-SYSTEM.CONF(5)
systemd-system.conf, systemd-user.conf - System and session service manager configuration file
When run as system instance systemd reads the configuration file system.conf, otherwise user.conf. These configuration files contain a few
settings controlling basic manager operations.
All options are configured in the "[Manager]" section:
LogLevel=, LogTarget=, LogColor=, LogLocation=, DumpCore=yes, CrashShell=no, ShowStatus=yes, CrashChVT=1, DefaultStandardOutput=journal,
Configures various parameters of basic manager operation. These options may be overridden by the respective command line arguments. See
systemd(1) for details about these command line arguments.
DefaultTimeoutStartSec=, DefaultTimeoutStopSec=, DefaultRestartSec=
Configures the default time-outs for starting and stopping of units, as well as the default time to sleep between automatic restarts of
a units, as configured per-unit in TimeoutStartSec=, TimeoutStopSec= and RestartSec= (for service units see systemd.service(5) for
details on the per-unit settings). For non-service units DefaultTimeoutStartSec= sets the default TimeoutSec= value.
Configure the default start rate limiting, as configured per-service by StartLimitInterval= and StartLimitBurst=. See
systemd.service(5) for details on the per-service settings).
Configures the initial CPU affinity for the init process. Takes a space-separated list of CPU indexes.
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.
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.
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.
Sets the timer slack in nanoseconds for PID 1 which is then inherited to 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 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.
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.
DefaultEnvironment="VAR1=word1 word2" VAR2=word3 "VAR3=word 5 6"
Sets three variables "VAR1", "VAR2", "VAR3".
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. Use the string infinity to configure no
limit on a specific resource. 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.
systemd(1), systemd.directives(7), environ(7)
systemd 208 SYSTEMD-SYSTEM.CONF(5)