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SYSTEMD-SYSTEM.CONF(5)        systemd-system.conf       SYSTEMD-SYSTEM.CONF(5)
NAME
       systemd-system.conf, system.conf.d, systemd-user.conf, user.conf.d -
       System and session service manager configuration files
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; 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. See
       systemd.syntax(5) for a general description of the syntax.
CONFIGURATION DIRECTORIES AND PRECEDENCE
       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. When multiple files specify the same option, for options
       which accept just a single value, the entry in the file with the
       lexicographically latest name takes precedence. For options which
       accept a list of values, entries are collected as they occur in files
       sorted lexicographically. 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,
       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 CPU affinity for the service manager as well as the
           default CPU affinity for all forked off processes. 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. This option may be specified more than once, in which
           case the specified CPU affinity masks are merged. If the empty
           string is assigned, the mask is reset, all assignments prior to
           this will have no effect. Individual services may override the CPU
           affinity for their processes with the CPUAffinity= setting in unit
           files, see systemd.exec(5).
       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.
       NUMAPolicy=
           Configures the NUMA memory policy for the service manager and the
           default NUMA memory policy for all forked off processes. Individual
           services may override the default policy with the NUMAPolicy=
           setting in unit files, see systemd.exec(5).
       NUMAMask=
           Configures the NUMA node mask that will be associated with the
           selected NUMA policy. Note that default and local NUMA policies
           don't require explicit NUMA node mask and value of the option can
           be empty. Similarly to NUMAPolicy=, value can be overriden by
           individual services in unit files, see systemd.exec(5).
       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 or the path
           specified with WatchdogDevice= or the kernel option
           systemd.watchdog-device=) 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 all possible reboot timeout
           values, 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. Note that the ShutdownWatchdogSec= timeout applies only
           to the second phase of the reboot, i.e. after all regular services
           are already terminated, and after the system and service manager
           process (PID 1) got replaced by the systemd-shutdown binary, see
           system bootup(7) for details. During the first phase of the
           shutdown operation the system and service manager remains running
           and hence RuntimeWatchdogSec= is still honoured. In order to define
           a timeout on this first phase of system shutdown, configure
           JobTimeoutSec= and JobTimeoutAction= in the "[Unit]" section of the
           shutdown.target unit. By default RuntimeWatchdogSec= defaults to 0
           (off), and ShutdownWatchdogSec= to 10min. These settings have no
           effect if a hardware watchdog is not available.
       WatchdogDevice=
           Configure the hardware watchdog device that the runtime and
           shutdown watchdog timers will open and use. Defaults to
           /dev/watchdog. This setting has 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.
       NoNewPrivileges=
           Takes a boolean argument. If true, ensures that PID 1 and all its
           children can never gain new privileges through execve(2) (e.g. via
           setuid or setgid bits, or filesystem capabilities). Defaults to
           false. General purpose distributions commonly rely on executables
           with setuid or setgid bits and will thus not function properly with
           this option enabled. Individual units cannot disable this option.
           Also see No New Privileges Flag[1].
       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.
       DefaultDeviceTimeoutSec=
           Configures the default timeout for waiting for devices. It can be
           changed per device via the x-systemd.device-timeout= option in
           /etc/fstab and /etc/crypttab (see systemd.mount(5), crypttab(5)).
           Defaults to 90s.
       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=, DefaultIPAccounting=
           Configure the default resource accounting settings, as configured
           per-unit by CPUAccounting=, BlockIOAccounting=, MemoryAccounting=,
           TasksAccounting= and IPAccounting=. See systemd.resource-control(5)
           for details on the per-unit settings.  DefaultTasksAccounting=
           defaults to on, DefaultMemoryAccounting= to yes, 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 80%, which equals 26214 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
       systemd(1), systemd.directives(7), systemd.exec(5), systemd.service(5),
       environ(7), capabilities(7)
NOTES
        1. No New Privileges Flag
           https://www.kernel.org/doc/html/latest/userspace-api/no_new_privs.html
systemd 239                                             SYSTEMD-SYSTEM.CONF(5)