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systemd-system.conf



SYNOPSIS

       /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

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


CONFIGURATION DIRECTORIES AND PRECEDENCE

       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

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

       LogLevel=, LogTarget=, LogColor=, LogLocation=, DumpCore=yes,
       CrashShell=no, ShowStatus=yes, CrashChVT=1,
       DefaultStandardOutput=journal, DefaultStandardError=inherit
           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.

       CtrlAltDelBurstAction=
           Defines what action will be performed if user presses
           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
           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.

       DefaultStartLimitInterval=, DefaultStartLimitBurst=
           Configure the default unit start rate limiting, as configured
           per-service by StartLimitInterval= and StartLimitBurst=. See
           systemd.service(5) for details on the per-service settings.

       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.

       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
           (=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

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


systemd 219 SYSTEMD-SYSTEM.CONF(5)



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