1SYSTEMD-SYSTEM.CONF(5) systemd-system.conf SYSTEMD-SYSTEM.CONF(5)
2
6 systemd-system.conf, system.conf.d, systemd-user.conf, user.conf.d -
7 System and session service manager configuration files
8
10 /etc/systemd/system.conf, /etc/systemd/system.conf.d/*.conf,
11 /run/systemd/system.conf.d/*.conf,
12 /usr/lib/systemd/system.conf.d/*.conf
13 /etc/systemd/user.conf, /etc/systemd/user.conf.d/*.conf,
15 /run/systemd/user.conf.d/*.conf, /usr/lib/systemd/user.conf.d/*.conf
16
18 When run as a system instance, systemd interprets the configuration
19 file system.conf and the files in system.conf.d directories. These
20 configuration files contain a few settings controlling basic manager
21 operations.
22
24 Default configuration is defined during compilation, so a configuration
25 file is only needed when it is necessary to deviate from those
26 defaults. By default the configuration file in /etc/systemd/ contains
27 commented out entries showing the defaults as a guide to the
28 administrator. This file can be edited to create local overrides.
29 When packages need to customize the configuration, they can install
31 configuration snippets in /usr/lib/systemd/*.conf.d/. Files in /etc/
32 are reserved for the local administrator, who may use this logic to
33 override the configuration files installed by vendor packages. The main
34 configuration file is read before any of the configuration directories,
35 and has the lowest precedence; entries in a file in any configuration
36 directory override entries in the single configuration file. Files in
37 the *.conf.d/ configuration subdirectories are sorted by their filename
38 in lexicographic order, regardless of which of the subdirectories they
39 reside in. If multiple files specify the same option, the entry in the
40 file with the lexicographically latest name takes precedence. It is
41 recommended to prefix all filenames in those subdirectories with a
42 two-digit number and a dash, to simplify the ordering of the files.
43 To disable a configuration file supplied by the vendor, the recommended
45 way is to place a symlink to /dev/null in the configuration directory
46 in /etc/, with the same filename as the vendor configuration file.
47
49 All options are configured in the "[Manager]" section:
50 LogLevel=, LogTarget=, LogColor=, LogLocation=, DumpCore=yes,
52 CrashShell=no, ShowStatus=yes, CrashChVT=1,
53 DefaultStandardOutput=journal, DefaultStandardError=inherit
54 Configures various parameters of basic manager operation. These
55 options may be overridden by the respective command line arguments.
56 See systemd(1) for details about these command line arguments.
57 CtrlAltDelBurstAction=
59 Defines what action will be performed if user presses
60 Ctrl-Alt-Delete more than 7 times in 2s. Can be set to
61 "reboot-force", "poweroff-force", "reboot-immediate",
62 "poweroff-immediate" or disabled with "none". Defaults to
63 "reboot-force".
64 CPUAffinity=
66 Configures the initial CPU affinity for the init process. Takes a
67 list of CPU indices or ranges separated by either whitespace or
68 commas. CPU ranges are specified by the lower and upper CPU indices
69 separated by a dash.
70 JoinControllers=cpu,cpuacct net_cls,netprio
72 Configures controllers that shall be mounted in a single hierarchy.
73 By default, systemd will mount all controllers which are enabled in
74 the kernel in individual hierarchies, with the exception of those
75 listed in this setting. Takes a space-separated list of
76 comma-separated controller names, in order to allow multiple joined
77 hierarchies. Defaults to 'cpu,cpuacct'. Pass an empty string to
78 ensure that systemd mounts all controllers in separate hierarchies.
79 Note that this option is only applied once, at very early boot. If
81 you use an initial RAM disk (initrd) that uses systemd, it might
82 hence be necessary to rebuild the initrd if this option is changed,
83 and make sure the new configuration file is included in it.
84 Otherwise, the initrd might mount the controller hierarchies in a
85 different configuration than intended, and the main system cannot
86 remount them anymore.
87 RuntimeWatchdogSec=, ShutdownWatchdogSec=
89 Configure the hardware watchdog at runtime and at reboot. Takes a
90 timeout value in seconds (or in other time units if suffixed with
91 "ms", "min", "h", "d", "w"). If RuntimeWatchdogSec= is set to a
92 non-zero value, the watchdog hardware (/dev/watchdog) will be
93 programmed to automatically reboot the system if it is not
94 contacted within the specified timeout interval. The system manager
95 will ensure to contact it at least once in half the specified
96 timeout interval. This feature requires a hardware watchdog device
97 to be present, as it is commonly the case in embedded and server
98 systems. Not all hardware watchdogs allow configuration of the
99 reboot timeout, in which case the closest available timeout is
100 picked. ShutdownWatchdogSec= may be used to configure the hardware
101 watchdog when the system is asked to reboot. It works as a safety
102 net to ensure that the reboot takes place even if a clean reboot
103 attempt times out. By default RuntimeWatchdogSec= defaults to 0
104 (off), and ShutdownWatchdogSec= to 10min. These settings have no
105 effect if a hardware watchdog is not available.
106 CapabilityBoundingSet=
108 Controls which capabilities to include in the capability bounding
109 set for PID 1 and its children. See capabilities(7) for details.
110 Takes a whitespace-separated list of capability names as read by
111 cap_from_name(3). Capabilities listed will be included in the
112 bounding set, all others are removed. If the list of capabilities
113 is prefixed with ~, all but the listed capabilities will be
114 included, the effect of the assignment inverted. Note that this
115 option also affects the respective capabilities in the effective,
116 permitted and inheritable capability sets. The capability bounding
117 set may also be individually configured for units using the
118 CapabilityBoundingSet= directive for units, but note that
119 capabilities dropped for PID 1 cannot be regained in individual
120 units, they are lost for good.
121 SystemCallArchitectures=
123 Takes a space-separated list of architecture identifiers. Selects
124 from which architectures system calls may be invoked on this
125 system. This may be used as an effective way to disable invocation
126 of non-native binaries system-wide, for example to prohibit
127 execution of 32-bit x86 binaries on 64-bit x86-64 systems. This
128 option operates system-wide, and acts similar to the
129 SystemCallArchitectures= setting of unit files, see systemd.exec(5)
130 for details. This setting defaults to the empty list, in which case
131 no filtering of system calls based on architecture is applied.
132 Known architecture identifiers are "x86", "x86-64", "x32", "arm"
133 and the special identifier "native". The latter implicitly maps to
134 the native architecture of the system (or more specifically, the
135 architecture the system manager was compiled for). Set this setting
136 to "native" to prohibit execution of any non-native binaries. When
137 a binary executes a system call of an architecture that is not
138 listed in this setting, it will be immediately terminated with the
139 SIGSYS signal.
140 TimerSlackNSec=
142 Sets the timer slack in nanoseconds for PID 1, which is inherited
143 by all executed processes, unless overridden individually, for
144 example with the TimerSlackNSec= setting in service units (for
145 details see systemd.exec(5)). The timer slack controls the accuracy
146 of wake-ups triggered by system timers. See prctl(2) for more
147 information. Note that in contrast to most other time span
148 definitions this parameter takes an integer value in nano-seconds
149 if no unit is specified. The usual time units are understood too.
150 DefaultTimerAccuracySec=
152 Sets the default accuracy of timer units. This controls the global
153 default for the AccuracySec= setting of timer units, see
154 systemd.timer(5) for details. AccuracySec= set in individual units
155 override the global default for the specific unit. Defaults to
156 1min. Note that the accuracy of timer units is also affected by the
157 configured timer slack for PID 1, see TimerSlackNSec= above.
158 DefaultTimeoutStartSec=, DefaultTimeoutStopSec=, DefaultRestartSec=
160 Configures the default timeouts for starting and stopping of units,
161 as well as the default time to sleep between automatic restarts of
162 units, as configured per-unit in TimeoutStartSec=, TimeoutStopSec=
163 and RestartSec= (for services, see systemd.service(5) for details
164 on the per-unit settings). For non-service units,
165 DefaultTimeoutStartSec= sets the default TimeoutSec= value.
166 DefaultStartLimitInterval=, DefaultStartLimitBurst=
168 Configure the default unit start rate limiting, as configured
169 per-service by StartLimitInterval= and StartLimitBurst=. See
170 systemd.service(5) for details on the per-service settings.
171 DefaultEnvironment=
173 Sets manager environment variables passed to all executed
174 processes. Takes a space-separated list of variable assignments.
175 See environ(7) for details about environment variables.
176 Example:
178 DefaultEnvironment="VAR1=word1 word2" VAR2=word3 "VAR3=word 5 6"
180 Sets three variables "VAR1", "VAR2", "VAR3".
182 DefaultCPUAccounting=, DefaultBlockIOAccounting=,
184 DefaultMemoryAccounting=, DefaultTasksAccounting=
185 Configure the default resource accounting settings, as configured
186 per-unit by CPUAccounting=, BlockIOAccounting=, MemoryAccounting=
187 and TasksAccounting=. See systemd.resource-control(5) for details
188 on the per-unit settings.
189 DefaultTasksMax=
191 Configure the default value for the per-unit TasksMax= setting. See
192 systemd.resource-control(5) for details. This setting applies to
193 all unit types that support resource control settings, with the
194 exception of slice units.
195 DefaultLimitCPU=, DefaultLimitFSIZE=, DefaultLimitDATA=,
197 DefaultLimitSTACK=, DefaultLimitCORE=, DefaultLimitRSS=,
198 DefaultLimitNOFILE=, DefaultLimitAS=, DefaultLimitNPROC=,
199 DefaultLimitMEMLOCK=, DefaultLimitLOCKS=, DefaultLimitSIGPENDING=,
200 DefaultLimitMSGQUEUE=, DefaultLimitNICE=, DefaultLimitRTPRIO=,
201 DefaultLimitRTTIME=
202 These settings control various default resource limits for units.
203 See setrlimit(2) for details. The resource limit is possible to
204 specify in two formats, value to set soft and hard limits to the
205 same value, or soft:hard to set both limits individually (e.g.
206 DefaultLimitAS=4G:16G). Use the string infinity to configure no
207 limit on a specific resource. The multiplicative suffixes K
208 (=1024), M (=1024*1024) and so on for G, T, P and E may be used for
209 resource limits measured in bytes (e.g. DefaultLimitAS=16G). For
210 the limits referring to time values, the usual time units ms, s,
211 min, h and so on may be used (see systemd.time(7) for details).
212 Note that if no time unit is specified for DefaultLimitCPU= the
213 default unit of seconds is implied, while for DefaultLimitRTTIME=
214 the default unit of microseconds is implied. Also, note that the
215 effective granularity of the limits might influence their
216 enforcement. For example, time limits specified for
217 DefaultLimitCPU= will be rounded up implicitly to multiples of 1s.
218 These settings may be overridden in individual units using the
219 corresponding LimitXXX= directives. Note that these resource limits
220 are only defaults for units, they are not applied to PID 1 itself.
221
223 systemd(1), systemd.directives(7), systemd.exec(5), systemd.service(5),
224 environ(7), capabilities(7)
225systemd 219 SYSTEMD-SYSTEM.CONF(5)