systemd-user.conf(5) — Linux manual page


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,

       /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. See systemd.syntax(7) for a general description of the


       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

       When packages need to customize the configuration, they can install
       configuration snippets in /usr/lib/systemd/*.conf.d/ or
       /usr/local/lib/systemd/*.conf.d/. 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 in which of the subdirectories
       they reside. 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.

       Files in /etc/ are reserved for the local administrator, who may use
       this logic to override the configuration files installed by vendor
       packages. 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:

       LogColor=, LogLevel=, LogLocation=, LogTarget=, LogTime=,
       DumpCore=yes, CrashChangeVT=no, CrashShell=no, CrashReboot=no,
       ShowStatus=yes, DefaultStandardOutput=journal,
           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.

           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

           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).

           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).

           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 overridden by
           individual services in unit files, see systemd.exec(5).

       RuntimeWatchdogSec=, RebootWatchdogSec=, KExecWatchdogSec=
           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.  RebootWatchdogSec= 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 RebootWatchdogSec= 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 unit. By default
           RuntimeWatchdogSec= defaults to 0 (off), and RebootWatchdogSec=
           to 10min.  KExecWatchdogSec= may be used to additionally enable
           the watchdog when kexec is being executed rather than when
           rebooting. Note that if the kernel does not reset the watchdog on
           kexec (depending on the specific hardware and/or driver), in this
           case the watchdog might not get disabled after kexec succeeds and
           thus the system might get rebooted, unless RuntimeWatchdogSec= is
           also enabled at the same time. For this reason it is recommended
           to enable KExecWatchdogSec= only if RuntimeWatchdogSec= is also
           enabled. These settings have no effect if a hardware watchdog is
           not available.

           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.

           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.

           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].

           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

           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.

           Takes either name or description as the value. If name, the
           system manager will use unit names in status messages, instead of
           the longer and more informative descriptions set with
           Description=, see systemd.unit(5).

           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=

       DefaultTimeoutStartSec=, DefaultTimeoutStopSec=,
       DefaultTimeoutAbortSec=, DefaultRestartSec=
           Configures the default timeouts for starting, stopping and
           aborting of units, as well as the default time to sleep between
           automatic restarts of units, as configured per-unit in
           TimeoutStartSec=, TimeoutStopSec=, TimeoutAbortSec= and
           RestartSec= (for services, see systemd.service(5) for details on
           the per-unit settings). Disabled by default, when service with
           Type=oneshot is used. For non-service units,
           DefaultTimeoutStartSec= sets the default TimeoutSec= value.
           DefaultTimeoutStartSec= and DefaultTimeoutStopSec= default to
           90s.  DefaultTimeoutAbortSec= is not set by default so that all
           units fall back to TimeoutStopSec=.  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.

           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".

       DefaultCPUAccounting=, DefaultBlockIOAccounting=,
       DefaultMemoryAccounting=, DefaultTasksAccounting=,
       DefaultIOAccounting=, DefaultIPAccounting=
           Configure the default resource accounting settings, as configured
           per-unit by CPUAccounting=, BlockIOAccounting=,
           MemoryAccounting=, TasksAccounting=, IOAccounting= and
           IPAccounting=. See systemd.resource-control(5) for details on the
           per-unit settings.  DefaultTasksAccounting= defaults to yes,
           DefaultMemoryAccounting= to yes.  DefaultCPUAccounting= defaults
           to yes if enabling CPU accounting doesn't require the CPU
           controller to be enabled (Linux 4.15+ using the unified hierarchy
           for resource control), otherwise it defaults to no. The other
           three settings default to no.

           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=,
           These settings control various default resource limits for
           processes executed by units. See setrlimit(2) for details. These
           settings may be overridden in individual units using the
           corresponding LimitXXX= directives and they accept the same
           parameter syntax, see systemd.exec(5) for details. Note that
           these resource limits are only defaults for units, they are not
           applied to the service manager process (i.e. PID 1) itself.

           Configure the default policy for reacting to processes being
           killed by the Linux Out-Of-Memory (OOM) killer. This may be used
           to pick a global default for the per-unit OOMPolicy= setting. See
           systemd.service(5) for details. Note that this default is not
           used for services that have Delegate= turned on.

SEE ALSO         top

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

NOTES         top

        1. No New Privileges Flag

COLOPHON         top

       This page is part of the systemd (systemd system and service manager)
       project.  Information about the project can be found at 
       ⟨⟩.  If you have a bug
       report for this manual page, see
       ⟨⟩.  This
       page was obtained from the project's upstream Git repository
       ⟨⟩ on 2020-11-01.  (At that
       time, the date of the most recent commit that was found in the repos‐
       itory was 2020-11-01.)  If you discover 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 im‐
       provements to the information in this COLOPHON (which is not part of
       the original manual page), send a mail to

systemd 247                                           SYSTEMD-SYSTEM.CONF(5)

Pages that refer to this page: init(1)systemd(1)30-systemd-environment-d-generator(7)systemd.index(7)systemd.syntax(7)