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

NAME | SYNOPSIS | DESCRIPTION | CONFIGURATION DIRECTORIES AND PRECEDENCE | OPTIONS | SPECIFIERS | HISTORY | SEE ALSO | NOTES | 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, /run/systemd/system.conf,
       /usr/lib/systemd/system.conf, /etc/systemd/system.conf.d/*.conf,
       /run/systemd/system.conf.d/*.conf,
       /usr/lib/systemd/system.conf.d/*.conf

       ~/.config/systemd/user.conf, /etc/systemd/user.conf,
       /run/systemd/user.conf, /usr/lib/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, it interprets the
       configuration file user.conf (in order of priority, in the home
       directory of the user and under /etc/systemd/, /run/systemd/, and
       /usr/lib/systemd/) 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 syntax.

CONFIGURATION DIRECTORIES AND PRECEDENCE         top

       The default configuration is set during compilation, so
       configuration is only needed when it is necessary to deviate from
       those defaults. The main configuration file is loaded from one of
       the listed directories in order of priority, only the first file
       found is used: /etc/systemd/, /run/systemd/,
       /usr/local/lib/systemd/ [1], /usr/lib/systemd/. The vendor
       version of the file contains commented out entries showing the
       defaults as a guide to the administrator. Local overrides can
       also be created by creating drop-ins, as described below. The
       main configuration file can also be edited for this purpose (or a
       copy in /etc/ if it's shipped under /usr/), however using
       drop-ins for local configuration is recommended over
       modifications to the main configuration file.

       In addition to the main configuration file, drop-in configuration
       snippets are read from /usr/lib/systemd/*.conf.d/,
       /usr/local/lib/systemd/*.conf.d/, and /etc/systemd/*.conf.d/.
       Those drop-ins have higher precedence and override the main
       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 sorted last
       takes precedence, and for options which accept a list of values,
       entries are collected as they occur in the sorted files.

       When packages need to customize the configuration, they can
       install drop-ins under /usr/. Files in /etc/ are reserved for the
       local administrator, who may use this logic to override the
       configuration files installed by vendor packages. Drop-ins have
       to be used to override package drop-ins, since the main
       configuration file has lower precedence. It is recommended to
       prefix all filenames in those subdirectories with a two-digit
       number and a dash, to simplify the ordering. This also defines a
       concept of drop-in priorities to allow OS vendors to ship
       drop-ins within a specific range lower than the range used by
       users. This should lower the risk of package drop-ins overriding
       accidentally drop-ins defined by users. It is recommended to use
       the range 10-40 for drop-ins in /usr/ and the range 60-90 for
       drop-ins in /etc/ and /run/, to make sure that local and
       transient drop-ins take priority over drop-ins shipped by the OS
       vendor.

       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,
       CrashAction=freeze, 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.

           Added in version 198.

       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".

           Added in version 232.

       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).

           Added in version 198.

       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).

           Added in version 243.

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

           Added in version 243.

       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"), or the special
           strings "off" or "default". If set to "off" (alternatively:
           "0") the watchdog logic is disabled: no watchdog device is
           opened, configured, or pinged. If set to the special string
           "default" the watchdog is opened and pinged in regular
           intervals, but the timeout is not changed from the default.
           If set to any other time value the watchdog timeout is
           configured to the specified value (or a value close to it,
           depending on hardware capabilities).

           If RuntimeWatchdogSec= is set to a non-zero value, the
           watchdog hardware (/dev/watchdog0 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 shutdown.target 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.

           Added in version 198.

       RuntimeWatchdogPreSec=
           Configure the hardware watchdog device pre-timeout value.
           Takes a timeout value in seconds (or in other time units
           similar to RuntimeWatchdogSec=). A watchdog pre-timeout is a
           notification generated by the watchdog before the watchdog
           reset might occur in the event the watchdog has not been
           serviced. This notification is handled by the kernel and can
           be configured to take an action (i.e. generate a kernel
           panic) using RuntimeWatchdogPreGovernor=. Not all watchdog
           hardware or drivers support generating a pre-timeout and
           depending on the state of the system, the kernel may be
           unable to take the configured action before the watchdog
           reboot. The watchdog will be configured to generate the
           pre-timeout event at the amount of time specified by
           RuntimeWatchdogPreSec= before the runtime watchdog timeout
           (set by RuntimeWatchdogSec=). For example, if the we have
           RuntimeWatchdogSec=30 and RuntimeWatchdogPreSec=10, then the
           pre-timeout event will occur if the watchdog has not pinged
           for 20s (10s before the watchdog would fire). By default,
           RuntimeWatchdogPreSec= defaults to 0 (off). The value set for
           RuntimeWatchdogPreSec= must be smaller than the timeout value
           for RuntimeWatchdogSec=. This setting has no effect if a
           hardware watchdog is not available or the hardware watchdog
           does not support a pre-timeout and will be ignored by the
           kernel if the setting is greater than the actual watchdog
           timeout.

           Added in version 251.

       RuntimeWatchdogPreGovernor=
           Configure the action taken by the hardware watchdog device
           when the pre-timeout expires. The default action for the
           pre-timeout event depends on the kernel configuration, but it
           is usually to log a kernel message. For a list of valid
           actions available for a given watchdog device, check the
           content of the
           /sys/class/watchdog/watchdogX/pretimeout_available_governors
           file. Typically, available governor types are noop and panic.
           Availability, names and functionality might vary depending on
           the specific device driver in use. If the
           pretimeout_available_governors sysfs file is empty, the
           governor might be built as a kernel module and might need to
           be manually loaded (e.g.  pretimeout_noop.ko), or the
           watchdog device might not support pre-timeouts.

           Added in version 251.

       WatchdogDevice=
           Configure the hardware watchdog device that the runtime and
           shutdown watchdog timers will open and use. Defaults to
           /dev/watchdog0. This setting has no effect if a hardware
           watchdog is not available.

           Added in version 236.

       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.

           Added in version 198.

       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[2].

           Added in version 239.

       ProtectSystem=
           Takes a boolean argument or the string "auto". If set to true
           this will remount /usr/ read-only. If set to "auto" (the
           default) and running in an initrd equivalent to true,
           otherwise false. This implements a restricted subset of the
           per-unit setting of the same name, see systemd.exec(5) for
           details: currently, the "full" or "struct" values are not
           supported.

           Added in version 256.

       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.

           Added in version 209.

       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.

           Added in version 198.

       StatusUnitFormat=
           Takes name, description or combined as the value. If name,
           the system manager will use unit names in status messages
           (e.g.  "systemd-journald.service"), instead of the longer and
           more informative descriptions set with Description= (e.g.
           "Journal Logging Service"). If combined, the system manager
           will use both unit names and descriptions in status messages
           (e.g.  "systemd-journald.service - Journal Logging Service").

           See systemd.unit(5) for details about unit names and
           Description=.

           Added in version 243.

       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.

           Added in version 212.

       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). For non-service units,
           DefaultTimeoutStartSec= sets the default TimeoutSec= value.

           DefaultTimeoutStartSec= and DefaultTimeoutStopSec= default to
           90 s in the system manager and 90 s in the user manager.
           DefaultTimeoutAbortSec= is not set by default so that all
           units fall back to TimeoutStopSec=.  DefaultRestartSec=
           defaults to 100 ms.

           Added in version 209.

       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 90 s in the system manager and 90 s
           in the user manager.

           Added in version 252.

       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.

           Added in version 209.

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

           Simple "%"-specifier expansion is supported, see below for a
           list of supported specifiers.

           Example:

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

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

           Added in version 205.

       ManagerEnvironment=
           Takes the same arguments as DefaultEnvironment=, see above.
           Sets environment variables just for the manager process
           itself. In contrast to user managers, these variables are not
           inherited by processes spawned by the system manager, use
           DefaultEnvironment= for that. Note that these variables are
           merged into the existing environment block. In particular, in
           case of the system manager, this includes variables set by
           the kernel based on the kernel command line.

           Setting environment variables for the manager process may be
           useful to modify its behaviour. See Known Environment
           Variables[3] for a descriptions of some variables understood
           by systemd.

           Simple "%"-specifier expansion is supported, see below for a
           list of supported specifiers.

           Added in version 248.

       DefaultCPUAccounting=, DefaultMemoryAccounting=,
       DefaultTasksAccounting=, DefaultIOAccounting=,
       DefaultIPAccounting=
           Configure the default resource accounting settings, as
           configured per-unit by CPUAccounting=, MemoryAccounting=,
           TasksAccounting=, IOAccounting= and IPAccounting=. See
           systemd.resource-control(5) for details on the per-unit
           settings.

           DefaultCPUAccounting= defaults to yes when running on kernel
           ≥4.15, and no on older versions.  DefaultMemoryAccounting=
           defaults to yes.  DefaultTasksAccounting= defaults to yes.
           The other settings default to no.

           Added in version 211.

       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% of the minimum of kernel.pid_max=, kernel.threads-max=
           and root cgroup pids.max. Kernel has a default value for
           kernel.pid_max= and an algorithm of counting in case of more
           than 32 cores. For example, with the default kernel.pid_max=,
           DefaultTasksMax= defaults to 4915, but might be greater in
           other systems or smaller in OS containers.

           Added in version 228.

       DefaultLimitCPU=, DefaultLimitFSIZE=, DefaultLimitDATA=,
       DefaultLimitSTACK=, DefaultLimitCORE=, DefaultLimitRSS=,
       DefaultLimitNOFILE=, DefaultLimitAS=, DefaultLimitNPROC=,
       DefaultLimitMEMLOCK=, DefaultLimitLOCKS=,
       DefaultLimitSIGPENDING=, DefaultLimitMSGQUEUE=,
       DefaultLimitNICE=, DefaultLimitRTPRIO=, DefaultLimitRTTIME=
           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.

           Most of these settings are unset, which means the resource
           limits are inherited from the kernel or, if invoked in a
           container, from the container manager. However, the following
           have defaults:

           •   DefaultLimitNOFILE= defaults to 1024:524288.

           •   DefaultLimitMEMLOCK= defaults to 8M.

           •   DefaultLimitCORE= does not have a default but it is worth
               mentioning that RLIMIT_CORE is set to "infinity" by PID 1
               which is inherited by its children.

           Note that the service manager internally in PID 1 bumps
           RLIMIT_NOFILE and RLIMIT_MEMLOCK to higher values, however
           the limit is reverted to the mentioned defaults for all child
           processes forked off.

           Added in version 198.

       DefaultOOMPolicy=
           Configure the default policy for reacting to processes being
           killed by the Linux Out-Of-Memory (OOM) killer or
           systemd-oomd. 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.

           Added in version 243.

       DefaultOOMScoreAdjust=
           Configures the default OOM score adjustments of processes run
           by the service manager. This defaults to unset (meaning the
           forked off processes inherit the service manager's OOM score
           adjustment value), except if the service manager is run for
           an unprivileged user, in which case this defaults to the
           service manager's OOM adjustment value plus 100 (this makes
           service processes slightly more likely to be killed under
           memory pressure than the manager itself). This may be used to
           pick a global default for the per-unit OOMScoreAdjust=
           setting. See systemd.exec(5) for details. Note that this
           setting has no effect on the OOM score adjustment value of
           the service manager process itself, it retains the original
           value set during its invocation.

           Added in version 250.

       DefaultSmackProcessLabel=
           Takes a SMACK64 security label as the argument. The process
           executed by a unit will be started under this label if
           SmackProcessLabel= is not set in the unit. See
           systemd.exec(5) for the details.

           If the value is "/", only labels specified with
           SmackProcessLabel= are assigned and the compile-time default
           is ignored.

           Added in version 252.

       ReloadLimitIntervalSec=, ReloadLimitBurst=
           Rate limiting for daemon-reload and (since v256)
           daemon-reexec requests. The setting applies to both
           operations, but the rate limits are tracked separately.
           Defaults to unset, and any number of operations can be
           requested at any time.  ReloadLimitIntervalSec= takes a value
           in seconds to configure the rate limit window, and
           ReloadLimitBurst= takes a positive integer to configure the
           maximum allowed number of operations within the configured
           time window.

           Added in version 253.

       DefaultMemoryPressureWatch=, DefaultMemoryPressureThresholdSec=
           Configures the default settings for the per-unit
           MemoryPressureWatch= and MemoryPressureThresholdSec=
           settings. See systemd.resource-control(5) for details.
           Defaults to "auto" and "200ms", respectively. This also sets
           the memory pressure monitoring threshold for the service
           manager itself.

           Added in version 254.

SPECIFIERS         top

       Specifiers may be used in the DefaultEnvironment= and
       ManagerEnvironment= settings. The following expansions are
       understood:

       Table 1. Specifiers available
       ┌───────────┬──────────────────┬────────────────────────┐
       │ Specifier Meaning          Details                │
       ├───────────┼──────────────────┼────────────────────────┤
       │ "%a"      │ Architecture     │ A short string         │
       │           │                  │ identifying the        │
       │           │                  │ architecture of        │
       │           │                  │ the local system.      │
       │           │                  │ A string such as       │
       │           │                  │ x86, x86-64 or         │
       │           │                  │ arm64. See the         │
       │           │                  │ architectures          │
       │           │                  │ defined for            │
       │           │                  │ ConditionArchitecture= │
       │           │                  │ in systemd.unit(5)     │
       │           │                  │ for a full list.       │
       ├───────────┼──────────────────┼────────────────────────┤
       │ "%A"      │ Operating system │ The operating system   │
       │           │ image version    │ image version          │
       │           │                  │ identifier of the      │
       │           │                  │ running system, as     │
       │           │                  │ read from the          │
       │           │                  │ IMAGE_VERSION= field   │
       │           │                  │ of /etc/os-release. If │
       │           │                  │ not set, resolves to   │
       │           │                  │ an empty string. See   │
       │           │                  │ os-release(5) for more │
       │           │                  │ information.           │
       ├───────────┼──────────────────┼────────────────────────┤
       │ "%b"      │ Boot ID          │ The boot ID of the     │
       │           │                  │ running system,        │
       │           │                  │ formatted as string.   │
       │           │                  │ See random(4) for more │
       │           │                  │ information.           │
       ├───────────┼──────────────────┼────────────────────────┤
       │ "%B"      │ Operating system │ The operating system   │
       │           │ build ID         │ build identifier of    │
       │           │                  │ the running system, as │
       │           │                  │ read from the          │
       │           │                  │ BUILD_ID= field of     │
       │           │                  │ /etc/os-release. If    │
       │           │                  │ not set, resolves to   │
       │           │                  │ an empty string. See   │
       │           │                  │ os-release(5) for more │
       │           │                  │ information.           │
       ├───────────┼──────────────────┼────────────────────────┤
       │ "%H"      │ Host name        │ The hostname of the    │
       │           │                  │ running system.        │
       ├───────────┼──────────────────┼────────────────────────┤
       │ "%l"      │ Short host name  │ The hostname of the    │
       │           │                  │ running system,        │
       │           │                  │ truncated at the first │
       │           │                  │ dot to remove any      │
       │           │                  │ domain component.      │
       ├───────────┼──────────────────┼────────────────────────┤
       │ "%m"      │ Machine ID       │ The machine ID of the  │
       │           │                  │ running system,        │
       │           │                  │ formatted as string.   │
       │           │                  │ See machine-id(5) for  │
       │           │                  │ more information.      │
       ├───────────┼──────────────────┼────────────────────────┤
       │ "%M"      │ Operating system │ The operating system   │
       │           │ image identifier │ image identifier of    │
       │           │                  │ the running system, as │
       │           │                  │ read from the          │
       │           │                  │ IMAGE_ID= field of     │
       │           │                  │ /etc/os-release. If    │
       │           │                  │ not set, resolves to   │
       │           │                  │ an empty string. See   │
       │           │                  │ os-release(5) for more │
       │           │                  │ information.           │
       ├───────────┼──────────────────┼────────────────────────┤
       │ "%o"      │ Operating system │ The operating system   │
       │           │ ID               │ identifier of the      │
       │           │                  │ running system, as     │
       │           │                  │ read from the ID=      │
       │           │                  │ field of               │
       │           │                  │ /etc/os-release. See   │
       │           │                  │ os-release(5) for more │
       │           │                  │ information.           │
       ├───────────┼──────────────────┼────────────────────────┤
       │ "%v"      │ Kernel release   │ Identical to uname -r  │
       │           │                  │ output.                │
       ├───────────┼──────────────────┼────────────────────────┤
       │ "%w"      │ Operating system │ The operating system   │
       │           │ version ID       │ version identifier of  │
       │           │                  │ the running system, as │
       │           │                  │ read from the          │
       │           │                  │ VERSION_ID= field of   │
       │           │                  │ /etc/os-release. If    │
       │           │                  │ not set, resolves to   │
       │           │                  │ an empty string. See   │
       │           │                  │ os-release(5) for more │
       │           │                  │ information.           │
       ├───────────┼──────────────────┼────────────────────────┤
       │ "%W"      │ Operating system │ The operating system   │
       │           │ variant ID       │ variant identifier of  │
       │           │                  │ the running system, as │
       │           │                  │ read from the          │
       │           │                  │ VARIANT_ID= field of   │
       │           │                  │ /etc/os-release. If    │
       │           │                  │ not set, resolves to   │
       │           │                  │ an empty string. See   │
       │           │                  │ os-release(5) for more │
       │           │                  │ information.           │
       ├───────────┼──────────────────┼────────────────────────┤
       │ "%T"      │ Directory for    │ This is either /tmp or │
       │           │ temporary files  │ the path "$TMPDIR",    │
       │           │                  │ "$TEMP" or "$TMP" are  │
       │           │                  │ set to. (Note that the │
       │           │                  │ directory may be       │
       │           │                  │ specified without a    │
       │           │                  │ trailing slash.)       │
       ├───────────┼──────────────────┼────────────────────────┤
       │ "%V"      │ Directory for    │ This is either         │
       │           │ larger and       │ /var/tmp or the path   │
       │           │ persistent       │ "$TMPDIR", "$TEMP" or  │
       │           │ temporary files  │ "$TMP" are set to.     │
       │           │                  │ (Note that the         │
       │           │                  │ directory may be       │
       │           │                  │ specified without a    │
       │           │                  │ trailing slash.)       │
       ├───────────┼──────────────────┼────────────────────────┤
       │ "%h"      │ User home        │ This is the home       │
       │           │ directory        │ directory of the user  │
       │           │                  │ running the service    │
       │           │                  │ manager instance.      │
       ├───────────┼──────────────────┼────────────────────────┤
       │ "%u"      │ Username         │ This is the username   │
       │           │                  │ of the user running    │
       │           │                  │ the service manager    │
       │           │                  │ instance.              │
       ├───────────┼──────────────────┼────────────────────────┤
       │ "%U"      │ User id          │ This is the user id of │
       │           │                  │ the user running the   │
       │           │                  │ service manager        │
       │           │                  │ instance.              │
       ├───────────┼──────────────────┼────────────────────────┤
       │ "%g"      │ Primary group    │ This is the primary    │
       │           │                  │ group of the user      │
       │           │                  │ running the service    │
       │           │                  │ manager instance.      │
       ├───────────┼──────────────────┼────────────────────────┤
       │ "%G"      │ Primary group id │ This is the primary    │
       │           │                  │ group id of the user   │
       │           │                  │ running the service    │
       │           │                  │ manager instance.      │
       ├───────────┼──────────────────┼────────────────────────┤
       │ "%s"      │ User shell       │ This is the shell of   │
       │           │                  │ the user running the   │
       │           │                  │ service manager        │
       │           │                  │ instance.              │
       ├───────────┼──────────────────┼────────────────────────┤
       │ "%%"      │ Single percent   │ Use "%%" in place of   │
       │           │ sign             │ "%" to specify a       │
       │           │                  │ single percent sign.   │
       └───────────┴──────────────────┴────────────────────────┘

HISTORY         top

       systemd 252
           Option DefaultBlockIOAccounting= was deprecated. Please
           switch to the unified cgroup hierarchy.

           Added in version 252.

SEE ALSO         top

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

NOTES         top

        1. 💣💥🧨💥💥💣 Please note that those configuration files must
           be available at all times. If /usr/local/ is a separate
           partition, it may not be available during early boot, and
           must not be used for configuration.

        2. No New Privileges Flag
           https://docs.kernel.org/userspace-api/no_new_privs.html

        3. Known Environment Variables
           https://systemd.io/ENVIRONMENT

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 2024-06-14.  (At that
       time, the date of the most recent commit that was found in the
       repository was 2024-06-13.)  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 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 257~devel                                 SYSTEMD-SYSTEM.CONF(5)

Pages that refer to this page: run0(1)systemctl(1)systemd(1)journald.conf(5)logind.conf(5)systemd.exec(5)systemd.mount(5)systemd.resource-control(5)systemd.scope(5)systemd.service(5)systemd.socket(5)systemd.swap(5)systemd.timer(5)systemd.unit(5)kernel-command-line(7)systemd.directives(7)systemd.index(7)systemd.syntax(7)systemd-oomd.service(8)