diff options
Diffstat (limited to '')
| -rw-r--r-- | man/systemd-system.conf.xml | 619 |
1 files changed, 619 insertions, 0 deletions
diff --git a/man/systemd-system.conf.xml b/man/systemd-system.conf.xml new file mode 100644 index 0000000..2bdfa1c --- /dev/null +++ b/man/systemd-system.conf.xml @@ -0,0 +1,619 @@ +<?xml version='1.0'?> +<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" + "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" [ +<!ENTITY % entities SYSTEM "custom-entities.ent" > +%entities; +]> +<!-- SPDX-License-Identifier: LGPL-2.1-or-later --> + +<refentry id="systemd-system.conf" + xmlns:xi="http://www.w3.org/2001/XInclude"> + <refentryinfo> + <title>systemd-system.conf</title> + <productname>systemd</productname> + </refentryinfo> + + <refmeta> + <refentrytitle>systemd-system.conf</refentrytitle> + <manvolnum>5</manvolnum> + </refmeta> + + <refnamediv> + <refname>systemd-system.conf</refname> + <refname>system.conf.d</refname> + <refname>systemd-user.conf</refname> + <refname>user.conf.d</refname> + <refpurpose>System and session service manager configuration files</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <para><filename>/etc/systemd/system.conf</filename>, + <filename>/etc/systemd/system.conf.d/*.conf</filename>, + <filename>/run/systemd/system.conf.d/*.conf</filename>, + <filename>/usr/lib/systemd/system.conf.d/*.conf</filename></para> + + <para><filename>~/.config/systemd/user.conf</filename>, + <filename>/etc/systemd/user.conf</filename>, + <filename>/etc/systemd/user.conf.d/*.conf</filename>, + <filename>/run/systemd/user.conf.d/*.conf</filename>, + <filename>/usr/lib/systemd/user.conf.d/*.conf</filename></para> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para>When run as a system instance, <command>systemd</command> interprets the configuration file + <filename>system.conf</filename> and the files in <filename>system.conf.d</filename> directories; when + run as a user instance, it interprets the configuration file <filename>user.conf</filename> (either in + the home directory of the user, or if not found, under <filename>/etc/systemd/</filename>) and the files + in <filename>user.conf.d</filename> directories. These configuration files contain a few settings + controlling basic manager operations.</para> + + <para>See + <citerefentry><refentrytitle>systemd.syntax</refentrytitle><manvolnum>7</manvolnum></citerefentry> for a + general description of the syntax.</para> + </refsect1> + + <xi:include href="standard-conf.xml" xpointer="main-conf" /> + + <refsect1> + <title>Options</title> + + <para>All options are configured in the + [Manager] section:</para> + + <variablelist class='config-directives'> + + <varlistentry> + <term><varname>LogColor=</varname></term> + <term><varname>LogLevel=</varname></term> + <term><varname>LogLocation=</varname></term> + <term><varname>LogTarget=</varname></term> + <term><varname>LogTime=</varname></term> + <term><varname>DumpCore=yes</varname></term> + <term><varname>CrashChangeVT=no</varname></term> + <term><varname>CrashShell=no</varname></term> + <term><varname>CrashReboot=no</varname></term> + <term><varname>ShowStatus=yes</varname></term> + <term><varname>DefaultStandardOutput=journal</varname></term> + <term><varname>DefaultStandardError=inherit</varname></term> + + <listitem><para>Configures various parameters of basic manager operation. These options may be overridden by + the respective process and kernel command line arguments. See + <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry> for + details.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>CtrlAltDelBurstAction=</varname></term> + + <listitem><para>Defines what action will be performed + if user presses Ctrl-Alt-Delete more than 7 times in 2s. + Can be set to <literal>reboot-force</literal>, <literal>poweroff-force</literal>, + <literal>reboot-immediate</literal>, <literal>poweroff-immediate</literal> + or disabled with <literal>none</literal>. Defaults to + <literal>reboot-force</literal>. + </para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>CPUAffinity=</varname></term> + + <listitem><para>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 + <varname>CPUAffinity=</varname> setting in unit files, see + <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>NUMAPolicy=</varname></term> + + <listitem><para>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 + <varname>NUMAPolicy=</varname> setting in unit files, see + <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>NUMAMask=</varname></term> + + <listitem><para>Configures the NUMA node mask that will be associated with the selected NUMA policy. Note that + <option>default</option> and <option>local</option> NUMA policies don't require explicit NUMA node mask and + value of the option can be empty. Similarly to <varname>NUMAPolicy=</varname>, value can be overridden + by individual services in unit files, see + <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>RuntimeWatchdogSec=</varname></term> + <term><varname>RebootWatchdogSec=</varname></term> + <term><varname>KExecWatchdogSec=</varname></term> + + <listitem><para>Configure the hardware watchdog at runtime and at reboot. Takes a timeout value in + seconds (or in other time units if suffixed with <literal>ms</literal>, <literal>min</literal>, + <literal>h</literal>, <literal>d</literal>, <literal>w</literal>), or the special strings + <literal>off</literal> or <literal>default</literal>. If set to <literal>off</literal> + (alternatively: <literal>0</literal>) the watchdog logic is disabled: no watchdog device is opened, + configured, or pinged. If set to the special string <literal>default</literal> 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).</para> + + <para>If <varname>RuntimeWatchdogSec=</varname> is set to a non-zero value, the watchdog hardware + (<filename>/dev/watchdog0</filename> or the path specified with <varname>WatchdogDevice=</varname> or + the kernel option <varname>systemd.watchdog-device=</varname>) 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.</para> + + <para><varname>RebootWatchdogSec=</varname> 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 <varname>RebootWatchdogSec=</varname> 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 + <filename>systemd-shutdown</filename> binary, see system + <citerefentry><refentrytitle>bootup</refentrytitle><manvolnum>7</manvolnum></citerefentry> for + details. During the first phase of the shutdown operation the system and service manager remains + running and hence <varname>RuntimeWatchdogSec=</varname> is still honoured. In order to define a + timeout on this first phase of system shutdown, configure <varname>JobTimeoutSec=</varname> and + <varname>JobTimeoutAction=</varname> in the [Unit] section of the + <filename>shutdown.target</filename> unit. By default <varname>RuntimeWatchdogSec=</varname> defaults + to 0 (off), and <varname>RebootWatchdogSec=</varname> to 10min.</para> + + <para><varname>KExecWatchdogSec=</varname> 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 + <varname>RuntimeWatchdogSec=</varname> is also enabled at the same time. For this reason it is + recommended to enable <varname>KExecWatchdogSec=</varname> only if + <varname>RuntimeWatchdogSec=</varname> is also enabled.</para> + + <para>These settings have no effect if a hardware watchdog is not available.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>RuntimeWatchdogPreSec=</varname></term> + + <listitem><para>Configure the hardware watchdog device pre-timeout value. + Takes a timeout value in seconds (or in other time units similar to + <varname>RuntimeWatchdogSec=</varname>). 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 <varname>RuntimeWatchdogPreGovernor=</varname>. + 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 + <varname>RuntimeWatchdogPreSec=</varname> before the runtime watchdog timeout + (set by <varname>RuntimeWatchdogSec=</varname>). For example, if the we have + <varname>RuntimeWatchdogSec=30</varname> and + <varname>RuntimeWatchdogPreSec=10</varname>, then the pre-timeout event + will occur if the watchdog has not pinged for 20s (10s before the + watchdog would fire). By default, <varname>RuntimeWatchdogPreSec=</varname> + defaults to 0 (off). The value set for <varname>RuntimeWatchdogPreSec=</varname> + must be smaller than the timeout value for <varname>RuntimeWatchdogSec=</varname>. + 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.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>RuntimeWatchdogPreGovernor=</varname></term> + + <listitem><para>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 + <filename>/sys/class/watchdog/watchdog<replaceable>X</replaceable>/pretimeout_available_governors</filename> + file. Typically, available governor types are <varname>noop</varname> and <varname>panic</varname>. + Availability, names and functionality might vary depending on the specific device driver + in use. If the <filename>pretimeout_available_governors</filename> sysfs file is empty, + the governor might be built as a kernel module and might need to be manually loaded + (e.g. <varname>pretimeout_noop.ko</varname>), or the watchdog device might not support + pre-timeouts.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>WatchdogDevice=</varname></term> + + <listitem><para>Configure the hardware watchdog device that the + runtime and shutdown watchdog timers will open and use. Defaults + to <filename>/dev/watchdog0</filename>. This setting has no + effect if a hardware watchdog is not available.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>CapabilityBoundingSet=</varname></term> + + <listitem><para>Controls which capabilities to include in the + capability bounding set for PID 1 and its children. See + <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry> + for details. Takes a whitespace-separated list of capability + names as read by + <citerefentry project='mankier'><refentrytitle>cap_from_name</refentrytitle><manvolnum>3</manvolnum></citerefentry>. + 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 <varname>CapabilityBoundingSet=</varname> directive + for units, but note that capabilities dropped for PID 1 cannot + be regained in individual units, they are lost for + good.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>NoNewPrivileges=</varname></term> + + <listitem><para>Takes a boolean argument. If true, ensures that PID 1 + and all its children can never gain new privileges through + <citerefentry project='man-pages'><refentrytitle>execve</refentrytitle><manvolnum>2</manvolnum></citerefentry> + (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 <ulink url="https://docs.kernel.org/userspace-api/no_new_privs.html">No New Privileges Flag</ulink>. + </para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>SystemCallArchitectures=</varname></term> + + <listitem><para>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 + <varname>SystemCallArchitectures=</varname> setting of unit + files, see + <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry> + 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 + <literal>x86</literal>, <literal>x86-64</literal>, + <literal>x32</literal>, <literal>arm</literal> and the special + identifier <literal>native</literal>. 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 <literal>native</literal> 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.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>TimerSlackNSec=</varname></term> + + <listitem><para>Sets the timer slack in nanoseconds for PID 1, + which is inherited by all executed processes, unless + overridden individually, for example with the + <varname>TimerSlackNSec=</varname> setting in service units + (for details see + <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>). + The timer slack controls the accuracy of wake-ups triggered by + system timers. See + <citerefentry><refentrytitle>prctl</refentrytitle><manvolnum>2</manvolnum></citerefentry> + 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.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>StatusUnitFormat=</varname></term> + + <listitem><para>Takes <option>name</option>, <option>description</option> or + <option>combined</option> as the value. If <option>name</option>, the system manager will use unit + names in status messages (e.g. <literal>systemd-journald.service</literal>), instead of the longer + and more informative descriptions set with <varname>Description=</varname> (e.g. <literal>Journal + Logging Service</literal>). If <option>combined</option>, the system manager will use both unit names + and descriptions in status messages (e.g. <literal>systemd-journald.service - Journal Logging + Service</literal>).</para> + + <para>See + <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry> for + details about unit names and <varname>Description=</varname>.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>DefaultTimerAccuracySec=</varname></term> + + <listitem><para>Sets the default accuracy of timer units. This + controls the global default for the + <varname>AccuracySec=</varname> setting of timer units, see + <citerefentry><refentrytitle>systemd.timer</refentrytitle><manvolnum>5</manvolnum></citerefentry> + for details. <varname>AccuracySec=</varname> 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 + <varname>TimerSlackNSec=</varname> above.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>DefaultTimeoutStartSec=</varname></term> + <term><varname>DefaultTimeoutStopSec=</varname></term> + <term><varname>DefaultTimeoutAbortSec=</varname></term> + <term><varname>DefaultRestartSec=</varname></term> + + <listitem><para>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 + <varname>TimeoutStartSec=</varname>, + <varname>TimeoutStopSec=</varname>, + <varname>TimeoutAbortSec=</varname> and + <varname>RestartSec=</varname> (for services, see + <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry> + for details on the per-unit settings). Disabled by default, when + service with <varname>Type=oneshot</varname> is used. + For non-service units, + <varname>DefaultTimeoutStartSec=</varname> sets the default + <varname>TimeoutSec=</varname> + value. <varname>DefaultTimeoutStartSec=</varname> and + <varname>DefaultTimeoutStopSec=</varname> default to + 90s. <varname>DefaultTimeoutAbortSec=</varname> is not set by default + so that all units fall back to <varname>TimeoutStopSec=</varname>. + <varname>DefaultRestartSec=</varname> defaults to + 100ms.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>DefaultDeviceTimeoutSec=</varname></term> + + <listitem><para>Configures the default timeout for waiting for devices. It can be changed per + device via the <varname>x-systemd.device-timeout=</varname> option in <filename>/etc/fstab</filename> + and <filename>/etc/crypttab</filename> (see + <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>, + <citerefentry><refentrytitle>crypttab</refentrytitle><manvolnum>5</manvolnum></citerefentry>). + Defaults to 90s.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>DefaultStartLimitIntervalSec=</varname></term> + <term><varname>DefaultStartLimitBurst=</varname></term> + + <listitem><para>Configure the default unit start rate + limiting, as configured per-service by + <varname>StartLimitIntervalSec=</varname> and + <varname>StartLimitBurst=</varname>. See + <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry> + for details on the per-service settings. + <varname>DefaultStartLimitIntervalSec=</varname> defaults to + 10s. <varname>DefaultStartLimitBurst=</varname> defaults to + 5.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>DefaultEnvironment=</varname></term> + + <listitem><para>Configures environment variables passed to all executed processes. Takes a + space-separated list of variable assignments. See <citerefentry + project='man-pages'><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry> for + details about environment variables.</para> + + <para>Simple <literal>%</literal>-specifier expansion is supported, see below for a list of supported + specifiers.</para> + + <para>Example: + + <programlisting>DefaultEnvironment="VAR1=word1 word2" VAR2=word3 "VAR3=word 5 6"</programlisting> + + Sets three variables + <literal>VAR1</literal>, + <literal>VAR2</literal>, + <literal>VAR3</literal>.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>ManagerEnvironment=</varname></term> + + <listitem><para>Takes the same arguments as <varname>DefaultEnvironment=</varname>, 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 <varname>DefaultEnvironment=</varname> + 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.</para> + + <para>Setting environment variables for the manager process may be useful to modify its behaviour. + See <ulink url="https://systemd.io/ENVIRONMENT">ENVIRONMENT</ulink> for a descriptions of some + variables understood by <command>systemd</command>.</para> + + <para>Simple <literal>%</literal>-specifier expansion is supported, see below for a list of supported + specifiers.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>DefaultCPUAccounting=</varname></term> + <term><varname>DefaultMemoryAccounting=</varname></term> + <term><varname>DefaultTasksAccounting=</varname></term> + <term><varname>DefaultIOAccounting=</varname></term> + <term><varname>DefaultIPAccounting=</varname></term> + + <listitem><para>Configure the default resource accounting settings, as configured per-unit by + <varname>CPUAccounting=</varname>, <varname>MemoryAccounting=</varname>, + <varname>TasksAccounting=</varname>, <varname>IOAccounting=</varname> and + <varname>IPAccounting=</varname>. See + <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry> + for details on the per-unit settings. <varname>DefaultTasksAccounting=</varname> defaults to yes, + <varname>DefaultMemoryAccounting=</varname> to &MEMORY_ACCOUNTING_DEFAULT;. + <varname>DefaultCPUAccounting=</varname> defaults to yes, but really has no effect if enabling CPU + accounting doesn't require the <option>cpu</option> 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.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>DefaultTasksMax=</varname></term> + + <listitem><para>Configure the default value for the per-unit <varname>TasksMax=</varname> setting. See + <citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry> + 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 <varname>kernel.pid_max=</varname>, <varname>kernel.threads-max=</varname> + and root cgroup <varname>pids.max</varname>. + Kernel has a default value for <varname>kernel.pid_max=</varname> and an algorithm of counting in case of more than 32 cores. + For example with the default <varname>kernel.pid_max=</varname>, <varname>DefaultTasksMax=</varname> defaults to 4915, + but might be greater in other systems or smaller in OS containers.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>DefaultLimitCPU=</varname></term> + <term><varname>DefaultLimitFSIZE=</varname></term> + <term><varname>DefaultLimitDATA=</varname></term> + <term><varname>DefaultLimitSTACK=</varname></term> + <term><varname>DefaultLimitCORE=</varname></term> + <term><varname>DefaultLimitRSS=</varname></term> + <term><varname>DefaultLimitNOFILE=</varname></term> + <term><varname>DefaultLimitAS=</varname></term> + <term><varname>DefaultLimitNPROC=</varname></term> + <term><varname>DefaultLimitMEMLOCK=</varname></term> + <term><varname>DefaultLimitLOCKS=</varname></term> + <term><varname>DefaultLimitSIGPENDING=</varname></term> + <term><varname>DefaultLimitMSGQUEUE=</varname></term> + <term><varname>DefaultLimitNICE=</varname></term> + <term><varname>DefaultLimitRTPRIO=</varname></term> + <term><varname>DefaultLimitRTTIME=</varname></term> + + <listitem><para>These settings control various default resource limits for processes executed by + units. See + <citerefentry><refentrytitle>setrlimit</refentrytitle><manvolnum>2</manvolnum></citerefentry> for + details. These settings may be overridden in individual units using the corresponding + <varname>LimitXXX=</varname> directives and they accept the same parameter syntax, + see <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry> + 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.</para> + + <para>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:</para> + <itemizedlist> + <listitem><para><varname>DefaultLimitNOFILE=</varname> defaults to 1024:&HIGH_RLIMIT_NOFILE;. + </para></listitem> + + <listitem><para><varname>DefaultLimitMEMLOCK=</varname> defaults to 8M.</para></listitem> + + <listitem><para><varname>DefaultLimitCORE=</varname> does not have a default but it is worth mentioning that + <varname>RLIMIT_CORE</varname> is set to <literal>infinity</literal> by PID 1 which is inherited by its + children.</para></listitem> + </itemizedlist> + + <para>Note that the service manager internally in PID 1 bumps <varname>RLIMIT_NOFILE</varname> and + <varname>RLIMIT_MEMLOCK</varname> to higher values, however the limit is reverted to the mentioned + defaults for all child processes forked off.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><varname>DefaultOOMPolicy=</varname></term> + + <listitem><para>Configure the default policy for reacting to processes being killed by the Linux + Out-Of-Memory (OOM) killer or <command>systemd-oomd</command>. This may be used to pick a global default for the per-unit + <varname>OOMPolicy=</varname> setting. See + <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry> + for details. Note that this default is not used for services that have <varname>Delegate=</varname> + turned on.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>DefaultOOMScoreAdjust=</varname></term> + + <listitem><para>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 <varname>OOMScoreAdjust=</varname> setting. See + <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry> 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.</para></listitem> + </varlistentry> + + <varlistentry> + <term><varname>DefaultSmackProcessLabel=</varname></term> + + <listitem><para>Takes a <option>SMACK64</option> security label as the argument. The process executed + by a unit will be started under this label if <varname>SmackProcessLabel=</varname> is not set in the + unit. See <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry> + for the details.</para> + + <para>If the value is <literal>/</literal>, only labels specified with <varname>SmackProcessLabel=</varname> + are assigned and the compile-time default is ignored.</para></listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>Specifiers</title> + + <para>Specifiers may be used in the <varname>DefaultEnvironment=</varname> and + <varname>ManagerEnvironment=</varname> settings. The following expansions are understood:</para> + <table class='specifiers'> + <title>Specifiers available</title> + <tgroup cols='3' align='left' colsep='1' rowsep='1'> + <colspec colname="spec" /> + <colspec colname="mean" /> + <colspec colname="detail" /> + <thead> + <row> + <entry>Specifier</entry> + <entry>Meaning</entry> + <entry>Details</entry> + </row> + </thead> + <tbody> + <xi:include href="standard-specifiers.xml" xpointer="a"/> + <xi:include href="standard-specifiers.xml" xpointer="A"/> + <xi:include href="standard-specifiers.xml" xpointer="b"/> + <xi:include href="standard-specifiers.xml" xpointer="B"/> + <xi:include href="standard-specifiers.xml" xpointer="H"/> + <xi:include href="standard-specifiers.xml" xpointer="l"/> + <xi:include href="standard-specifiers.xml" xpointer="m"/> + <xi:include href="standard-specifiers.xml" xpointer="M"/> + <xi:include href="standard-specifiers.xml" xpointer="o"/> + <xi:include href="standard-specifiers.xml" xpointer="v"/> + <xi:include href="standard-specifiers.xml" xpointer="w"/> + <xi:include href="standard-specifiers.xml" xpointer="W"/> + <xi:include href="standard-specifiers.xml" xpointer="T"/> + <xi:include href="standard-specifiers.xml" xpointer="V"/> + <xi:include href="standard-specifiers.xml" xpointer="percent"/> + </tbody> + </tgroup> + </table> + </refsect1> + + <refsect1> + <title>History</title> + + <variablelist> + <varlistentry> + <term>systemd 252</term> + <listitem><para>Option <varname>DefaultBlockIOAccounting=</varname> was deprecated. Please switch + to the unified cgroup hierarchy.</para></listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>See Also</title> + <para> + <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>, + <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry>, + <citerefentry project='man-pages'><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> |