894 lines
49 KiB
XML
894 lines
49 KiB
XML
<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->
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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
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<!--
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SPDX-License-Identifier: LGPL-2.1+
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-->
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<refentry id="systemd.resource-control">
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<refentryinfo>
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<title>systemd.resource-control</title>
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<productname>systemd</productname>
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<authorgroup>
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<author>
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<contrib>Developer</contrib>
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<firstname>Lennart</firstname>
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<surname>Poettering</surname>
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<email>lennart@poettering.net</email>
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</author>
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</authorgroup>
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</refentryinfo>
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<refmeta>
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<refentrytitle>systemd.resource-control</refentrytitle>
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<manvolnum>5</manvolnum>
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</refmeta>
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<refnamediv>
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<refname>systemd.resource-control</refname>
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<refpurpose>Resource control unit settings</refpurpose>
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</refnamediv>
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<refsynopsisdiv>
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<para>
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<filename><replaceable>slice</replaceable>.slice</filename>,
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<filename><replaceable>scope</replaceable>.scope</filename>,
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<filename><replaceable>service</replaceable>.service</filename>,
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<filename><replaceable>socket</replaceable>.socket</filename>,
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<filename><replaceable>mount</replaceable>.mount</filename>,
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<filename><replaceable>swap</replaceable>.swap</filename>
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</para>
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</refsynopsisdiv>
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<refsect1>
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<title>Description</title>
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<para>Unit configuration files for services, slices, scopes, sockets, mount points, and swap devices share a subset
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of configuration options for resource control of spawned processes. Internally, this relies on the Linux Control
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Groups (cgroups) kernel concept for organizing processes in a hierarchical tree of named groups for the purpose of
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resource management.</para>
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<para>This man page lists the configuration options shared by
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those six unit types. See
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<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>
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for the common options of all unit configuration files, and
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<citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
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<citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
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<citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
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<citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
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<citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
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and
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<citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>
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for more information on the specific unit configuration files. The
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resource control configuration options are configured in the
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[Slice], [Scope], [Service], [Socket], [Mount], or [Swap]
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sections, depending on the unit type.</para>
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<para>In addition, options which control resources available to programs
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<emphasis>executed</emphasis> by systemd are listed in
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<citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
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Those options complement options listed here.</para>
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<para>See the <ulink
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url="https://www.freedesktop.org/wiki/Software/systemd/ControlGroupInterface/">New
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Control Group Interfaces</ulink> for an introduction on how to make
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use of resource control APIs from programs.</para>
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</refsect1>
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<refsect1>
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<title>Implicit Dependencies</title>
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<para>The following dependencies are implicitly added:</para>
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<itemizedlist>
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<listitem><para>Units with the <varname>Slice=</varname> setting set automatically acquire
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<varname>Requires=</varname> and <varname>After=</varname> dependencies on the specified
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slice unit.</para></listitem>
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</itemizedlist>
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</refsect1>
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<!-- We don't have any default dependency here. -->
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<refsect1>
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<title>Unified and Legacy Control Group Hierarchies</title>
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<para>The unified control group hierarchy is the new version of kernel control group interface, see <ulink
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url="https://www.kernel.org/doc/Documentation/cgroup-v2.txt">cgroup-v2.txt</ulink>. Depending on the resource type,
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there are differences in resource control capabilities. Also, because of interface changes, some resource types
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have separate set of options on the unified hierarchy.</para>
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<para>
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<variablelist>
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<varlistentry>
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<term><option>CPU</option></term>
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<listitem>
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<para><varname>CPUWeight=</varname> and <varname>StartupCPUWeight=</varname> replace
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<varname>CPUShares=</varname> and <varname>StartupCPUShares=</varname>, respectively.</para>
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<para>The <literal>cpuacct</literal> controller does not exist separately on the unified hierarchy.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><option>Memory</option></term>
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<listitem>
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<para><varname>MemoryMax=</varname> replaces <varname>MemoryLimit=</varname>. <varname>MemoryLow=</varname>
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and <varname>MemoryHigh=</varname> are effective only on unified hierarchy.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><option>IO</option></term>
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<listitem>
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<para><varname>IO</varname> prefixed settings are a superset of and replace <varname>BlockIO</varname>
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prefixed ones. On unified hierarchy, IO resource control also applies to buffered writes.</para>
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</listitem>
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</varlistentry>
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</variablelist>
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</para>
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<para>To ease the transition, there is best-effort translation between the two versions of settings. For each
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controller, if any of the settings for the unified hierarchy are present, all settings for the legacy hierarchy are
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ignored. If the resulting settings are for the other type of hierarchy, the configurations are translated before
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application.</para>
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<para>Legacy control group hierarchy (see <ulink
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url="https://www.kernel.org/doc/Documentation/cgroup-v1/cgroups.txt">cgroups.txt</ulink>), also called cgroup-v1,
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doesn't allow safe delegation of controllers to unprivileged processes. If the system uses the legacy control group
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hierarchy, resource control is disabled for systemd user instance, see
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<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
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</para>
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</refsect1>
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<refsect1>
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<title>Options</title>
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<para>Units of the types listed above can have settings
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for resource control configuration:</para>
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<variablelist class='unit-directives'>
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<varlistentry>
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<term><varname>CPUAccounting=</varname></term>
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<listitem>
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<para>Turn on CPU usage accounting for this unit. Takes a
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boolean argument. Note that turning on CPU accounting for
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one unit will also implicitly turn it on for all units
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contained in the same slice and for all its parent slices
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and the units contained therein. The system default for this
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setting may be controlled with
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<varname>DefaultCPUAccounting=</varname> in
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<citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>CPUWeight=<replaceable>weight</replaceable></varname></term>
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<term><varname>StartupCPUWeight=<replaceable>weight</replaceable></varname></term>
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<listitem>
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<para>Assign the specified CPU time weight to the processes executed, if the unified control group hierarchy
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is used on the system. These options take an integer value and control the <literal>cpu.weight</literal>
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control group attribute. The allowed range is 1 to 10000. Defaults to 100. For details about this control
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group attribute, see <ulink
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url="https://www.kernel.org/doc/Documentation/cgroup-v2.txt">cgroup-v2.txt</ulink> and <ulink
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url="https://www.kernel.org/doc/Documentation/scheduler/sched-design-CFS.txt">sched-design-CFS.txt</ulink>.
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The available CPU time is split up among all units within one slice relative to their CPU time weight.</para>
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<para>While <varname>StartupCPUWeight=</varname> only applies to the startup phase of the system,
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<varname>CPUWeight=</varname> applies to normal runtime of the system, and if the former is not set also to
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the startup phase. Using <varname>StartupCPUWeight=</varname> allows prioritizing specific services at
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boot-up differently than during normal runtime.</para>
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<para>Implies <literal>CPUAccounting=true</literal>.</para>
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<para>These settings replace <varname>CPUShares=</varname> and <varname>StartupCPUShares=</varname>.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>CPUQuota=</varname></term>
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<listitem>
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<para>Assign the specified CPU time quota to the processes executed. Takes a percentage value, suffixed with
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"%". The percentage specifies how much CPU time the unit shall get at maximum, relative to the total CPU time
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available on one CPU. Use values > 100% for allotting CPU time on more than one CPU. This controls the
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<literal>cpu.max</literal> attribute on the unified control group hierarchy and
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<literal>cpu.cfs_quota_us</literal> on legacy. For details about these control group attributes, see <ulink
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url="https://www.kernel.org/doc/Documentation/cgroup-v2.txt">cgroup-v2.txt</ulink> and <ulink
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url="https://www.kernel.org/doc/Documentation/scheduler/sched-design-CFS.txt">sched-design-CFS.txt</ulink>.</para>
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<para>Example: <varname>CPUQuota=20%</varname> ensures that the executed processes will never get more than
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20% CPU time on one CPU.</para>
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<para>Implies <literal>CPUAccounting=true</literal>.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>MemoryAccounting=</varname></term>
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<listitem>
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<para>Turn on process and kernel memory accounting for this
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unit. Takes a boolean argument. Note that turning on memory
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accounting for one unit will also implicitly turn it on for
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all units contained in the same slice and for all its parent
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slices and the units contained therein. The system default
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for this setting may be controlled with
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<varname>DefaultMemoryAccounting=</varname> in
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<citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>MemoryLow=<replaceable>bytes</replaceable></varname></term>
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<listitem>
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<para>Specify the best-effort memory usage protection of the executed processes in this unit. If the memory
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usages of this unit and all its ancestors are below their low boundaries, this unit's memory won't be
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reclaimed as long as memory can be reclaimed from unprotected units.</para>
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<para>Takes a memory size in bytes. If the value is suffixed with K, M, G or T, the specified memory size is
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parsed as Kilobytes, Megabytes, Gigabytes, or Terabytes (with the base 1024), respectively. Alternatively, a
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percentage value may be specified, which is taken relative to the installed physical memory on the
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system. This controls the <literal>memory.low</literal> control group attribute. For details about this
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control group attribute, see <ulink
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url="https://www.kernel.org/doc/Documentation/cgroup-v2.txt">cgroup-v2.txt</ulink>.</para>
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<para>Implies <literal>MemoryAccounting=true</literal>.</para>
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<para>This setting is supported only if the unified control group hierarchy is used and disables
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<varname>MemoryLimit=</varname>.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>MemoryHigh=<replaceable>bytes</replaceable></varname></term>
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<listitem>
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<para>Specify the high limit on memory usage of the executed processes in this unit. Memory usage may go
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above the limit if unavoidable, but the processes are heavily slowed down and memory is taken away
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aggressively in such cases. This is the main mechanism to control memory usage of a unit.</para>
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<para>Takes a memory size in bytes. If the value is suffixed with K, M, G or T, the specified memory size is
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parsed as Kilobytes, Megabytes, Gigabytes, or Terabytes (with the base 1024), respectively. Alternatively, a
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percentage value may be specified, which is taken relative to the installed physical memory on the
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system. If assigned the
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special value <literal>infinity</literal>, no memory limit is applied. This controls the
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<literal>memory.high</literal> control group attribute. For details about this control group attribute, see
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<ulink url="https://www.kernel.org/doc/Documentation/cgroup-v2.txt">cgroup-v2.txt</ulink>.</para>
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<para>Implies <literal>MemoryAccounting=true</literal>.</para>
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<para>This setting is supported only if the unified control group hierarchy is used and disables
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<varname>MemoryLimit=</varname>.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>MemoryMax=<replaceable>bytes</replaceable></varname></term>
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<listitem>
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<para>Specify the absolute limit on memory usage of the executed processes in this unit. If memory usage
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cannot be contained under the limit, out-of-memory killer is invoked inside the unit. It is recommended to
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use <varname>MemoryHigh=</varname> as the main control mechanism and use <varname>MemoryMax=</varname> as the
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last line of defense.</para>
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<para>Takes a memory size in bytes. If the value is suffixed with K, M, G or T, the specified memory size is
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parsed as Kilobytes, Megabytes, Gigabytes, or Terabytes (with the base 1024), respectively. Alternatively, a
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percentage value may be specified, which is taken relative to the installed physical memory on the system. If
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assigned the special value <literal>infinity</literal>, no memory limit is applied. This controls the
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<literal>memory.max</literal> control group attribute. For details about this control group attribute, see
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<ulink url="https://www.kernel.org/doc/Documentation/cgroup-v2.txt">cgroup-v2.txt</ulink>.</para>
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<para>Implies <literal>MemoryAccounting=true</literal>.</para>
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<para>This setting replaces <varname>MemoryLimit=</varname>.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>MemorySwapMax=<replaceable>bytes</replaceable></varname></term>
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<listitem>
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<para>Specify the absolute limit on swap usage of the executed processes in this unit.</para>
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<para>Takes a swap size in bytes. If the value is suffixed with K, M, G or T, the specified swap size is
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parsed as Kilobytes, Megabytes, Gigabytes, or Terabytes (with the base 1024), respectively. If assigned the
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special value <literal>infinity</literal>, no swap limit is applied. This controls the
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<literal>memory.swap.max</literal> control group attribute. For details about this control group attribute,
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see <ulink url="https://www.kernel.org/doc/Documentation/cgroup-v2.txt">cgroup-v2.txt</ulink>.</para>
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<para>Implies <literal>MemoryAccounting=true</literal>.</para>
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<para>This setting is supported only if the unified control group hierarchy is used and disables
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<varname>MemoryLimit=</varname>.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>TasksAccounting=</varname></term>
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<listitem>
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<para>Turn on task accounting for this unit. Takes a
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boolean argument. If enabled, the system manager will keep
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track of the number of tasks in the unit. The number of
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tasks accounted this way includes both kernel threads and
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userspace processes, with each thread counting
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individually. Note that turning on tasks accounting for one
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unit will also implicitly turn it on for all units contained
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||
in the same slice and for all its parent slices and the
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units contained therein. The system default for this setting
|
||
may be controlled with
|
||
<varname>DefaultTasksAccounting=</varname> in
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||
<citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>TasksMax=<replaceable>N</replaceable></varname></term>
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||
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<listitem>
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<para>Specify the maximum number of tasks that may be created in the unit. This ensures that the number of
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tasks accounted for the unit (see above) stays below a specific limit. This either takes an absolute number
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of tasks or a percentage value that is taken relative to the configured maximum number of tasks on the
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||
system. If assigned the special value <literal>infinity</literal>, no tasks limit is applied. This controls
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||
the <literal>pids.max</literal> control group attribute. For details about this control group attribute, see
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||
<ulink url="https://www.kernel.org/doc/Documentation/cgroup-v1/pids.txt">pids.txt</ulink>.</para>
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||
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||
<para>Implies <literal>TasksAccounting=true</literal>. The
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||
system default for this setting may be controlled with
|
||
<varname>DefaultTasksMax=</varname> in
|
||
<citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
|
||
</listitem>
|
||
</varlistentry>
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||
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||
<varlistentry>
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||
<term><varname>IOAccounting=</varname></term>
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||
|
||
<listitem>
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||
<para>Turn on Block I/O accounting for this unit, if the unified control group hierarchy is used on the
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||
system. Takes a boolean argument. Note that turning on block I/O accounting for one unit will also implicitly
|
||
turn it on for all units contained in the same slice and all for its parent slices and the units contained
|
||
therein. The system default for this setting may be controlled with <varname>DefaultIOAccounting=</varname>
|
||
in
|
||
<citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
|
||
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||
<para>This setting replaces <varname>BlockIOAccounting=</varname> and disables settings prefixed with
|
||
<varname>BlockIO</varname> or <varname>StartupBlockIO</varname>.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
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||
<varlistentry>
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||
<term><varname>IOWeight=<replaceable>weight</replaceable></varname></term>
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||
<term><varname>StartupIOWeight=<replaceable>weight</replaceable></varname></term>
|
||
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||
<listitem>
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||
<para>Set the default overall block I/O weight for the executed processes, if the unified control group
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||
hierarchy is used on the system. Takes a single weight value (between 1 and 10000) to set the default block
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||
I/O weight. This controls the <literal>io.weight</literal> control group attribute, which defaults to
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||
100. For details about this control group attribute, see <ulink
|
||
url="https://www.kernel.org/doc/Documentation/cgroup-v2.txt">cgroup-v2.txt</ulink>. The available I/O
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||
bandwidth is split up among all units within one slice relative to their block I/O weight.</para>
|
||
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||
<para>While <varname>StartupIOWeight=</varname> only applies
|
||
to the startup phase of the system,
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||
<varname>IOWeight=</varname> applies to the later runtime of
|
||
the system, and if the former is not set also to the startup
|
||
phase. This allows prioritizing specific services at boot-up
|
||
differently than during runtime.</para>
|
||
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||
<para>Implies <literal>IOAccounting=true</literal>.</para>
|
||
|
||
<para>These settings replace <varname>BlockIOWeight=</varname> and <varname>StartupBlockIOWeight=</varname>
|
||
and disable settings prefixed with <varname>BlockIO</varname> or <varname>StartupBlockIO</varname>.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>IODeviceWeight=<replaceable>device</replaceable> <replaceable>weight</replaceable></varname></term>
|
||
|
||
<listitem>
|
||
<para>Set the per-device overall block I/O weight for the executed processes, if the unified control group
|
||
hierarchy is used on the system. Takes a space-separated pair of a file path and a weight value to specify
|
||
the device specific weight value, between 1 and 10000. (Example: "/dev/sda 1000"). The file path may be
|
||
specified as path to a block device node or as any other file, in which case the backing block device of the
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||
file system of the file is determined. This controls the <literal>io.weight</literal> control group
|
||
attribute, which defaults to 100. Use this option multiple times to set weights for multiple devices. For
|
||
details about this control group attribute, see <ulink
|
||
url="https://www.kernel.org/doc/Documentation/cgroup-v2.txt">cgroup-v2.txt</ulink>.</para>
|
||
|
||
<para>Implies <literal>IOAccounting=true</literal>.</para>
|
||
|
||
<para>This setting replaces <varname>BlockIODeviceWeight=</varname> and disables settings prefixed with
|
||
<varname>BlockIO</varname> or <varname>StartupBlockIO</varname>.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>IOReadBandwidthMax=<replaceable>device</replaceable> <replaceable>bytes</replaceable></varname></term>
|
||
<term><varname>IOWriteBandwidthMax=<replaceable>device</replaceable> <replaceable>bytes</replaceable></varname></term>
|
||
|
||
<listitem>
|
||
<para>Set the per-device overall block I/O bandwidth maximum limit for the executed processes, if the unified
|
||
control group hierarchy is used on the system. This limit is not work-conserving and the executed processes
|
||
are not allowed to use more even if the device has idle capacity. Takes a space-separated pair of a file
|
||
path and a bandwidth value (in bytes per second) to specify the device specific bandwidth. The file path may
|
||
be a path to a block device node, or as any other file in which case the backing block device of the file
|
||
system of the file is used. If the bandwidth is suffixed with K, M, G, or T, the specified bandwidth is
|
||
parsed as Kilobytes, Megabytes, Gigabytes, or Terabytes, respectively, to the base of 1000. (Example:
|
||
"/dev/disk/by-path/pci-0000:00:1f.2-scsi-0:0:0:0 5M"). This controls the <literal>io.max</literal> control
|
||
group attributes. Use this option multiple times to set bandwidth limits for multiple devices. For details
|
||
about this control group attribute, see <ulink
|
||
url="https://www.kernel.org/doc/Documentation/cgroup-v2.txt">cgroup-v2.txt</ulink>.
|
||
</para>
|
||
|
||
<para>Implies <literal>IOAccounting=true</literal>.</para>
|
||
|
||
<para>These settings replace <varname>BlockIOReadBandwidth=</varname> and
|
||
<varname>BlockIOWriteBandwidth=</varname> and disable settings prefixed with <varname>BlockIO</varname> or
|
||
<varname>StartupBlockIO</varname>.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>IOReadIOPSMax=<replaceable>device</replaceable> <replaceable>IOPS</replaceable></varname></term>
|
||
<term><varname>IOWriteIOPSMax=<replaceable>device</replaceable> <replaceable>IOPS</replaceable></varname></term>
|
||
|
||
<listitem>
|
||
<para>Set the per-device overall block I/O IOs-Per-Second maximum limit for the executed processes, if the
|
||
unified control group hierarchy is used on the system. This limit is not work-conserving and the executed
|
||
processes are not allowed to use more even if the device has idle capacity. Takes a space-separated pair of
|
||
a file path and an IOPS value to specify the device specific IOPS. The file path may be a path to a block
|
||
device node, or as any other file in which case the backing block device of the file system of the file is
|
||
used. If the IOPS is suffixed with K, M, G, or T, the specified IOPS is parsed as KiloIOPS, MegaIOPS,
|
||
GigaIOPS, or TeraIOPS, respectively, to the base of 1000. (Example:
|
||
"/dev/disk/by-path/pci-0000:00:1f.2-scsi-0:0:0:0 1K"). This controls the <literal>io.max</literal> control
|
||
group attributes. Use this option multiple times to set IOPS limits for multiple devices. For details about
|
||
this control group attribute, see <ulink
|
||
url="https://www.kernel.org/doc/Documentation/cgroup-v2.txt">cgroup-v2.txt</ulink>.
|
||
</para>
|
||
|
||
<para>Implies <literal>IOAccounting=true</literal>.</para>
|
||
|
||
<para>These settings are supported only if the unified control group hierarchy is used and disable settings
|
||
prefixed with <varname>BlockIO</varname> or <varname>StartupBlockIO</varname>.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>IPAccounting=</varname></term>
|
||
|
||
<listitem>
|
||
<para>Takes a boolean argument. If true, turns on IPv4 and IPv6 network traffic accounting for packets sent
|
||
or received by the unit. When this option is turned on, all IPv4 and IPv6 sockets created by any process of
|
||
the unit are accounted for.</para>
|
||
|
||
<para>When this option is used in socket units, it applies to all IPv4 and IPv6 sockets
|
||
associated with it (including both listening and connection sockets where this applies). Note that for
|
||
socket-activated services, this configuration setting and the accounting data of the service unit and the
|
||
socket unit are kept separate, and displayed separately. No propagation of the setting and the collected
|
||
statistics is done, in either direction. Moreover, any traffic sent or received on any of the socket unit's
|
||
sockets is accounted to the socket unit — and never to the service unit it might have activated, even if the
|
||
socket is used by it.</para>
|
||
|
||
<para>The system default for this setting may be controlled with <varname>DefaultIPAccounting=</varname> in
|
||
<citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>IPAddressAllow=<replaceable>ADDRESS[/PREFIXLENGTH]…</replaceable></varname></term>
|
||
<term><varname>IPAddressDeny=<replaceable>ADDRESS[/PREFIXLENGTH]…</replaceable></varname></term>
|
||
|
||
<listitem>
|
||
<para>Turn on address range network traffic filtering for packets sent and received over AF_INET and AF_INET6
|
||
sockets. Both directives take a space separated list of IPv4 or IPv6 addresses, each optionally suffixed
|
||
with an address prefix length (separated by a <literal>/</literal> character). If the latter is omitted, the
|
||
address is considered a host address, i.e. the prefix covers the whole address (32 for IPv4, 128 for IPv6).
|
||
</para>
|
||
|
||
<para>The access lists configured with this option are applied to all sockets created by processes of this
|
||
unit (or in the case of socket units, associated with it). The lists are implicitly combined with any lists
|
||
configured for any of the parent slice units this unit might be a member of. By default all access lists are
|
||
empty. When configured the lists are enforced as follows:</para>
|
||
|
||
<itemizedlist>
|
||
<listitem><para>Access will be granted in case its destination/source address matches any entry in the
|
||
<varname>IPAddressAllow=</varname> setting.</para></listitem>
|
||
|
||
<listitem><para>Otherwise, access will be denied in case its destination/source address matches any entry
|
||
in the <varname>IPAddressDeny=</varname> setting.</para></listitem>
|
||
|
||
<listitem><para>Otherwise, access will be granted.</para></listitem>
|
||
</itemizedlist>
|
||
|
||
<para>In order to implement a whitelisting IP firewall, it is recommended to use a
|
||
<varname>IPAddressDeny=</varname><constant>any</constant> setting on an upper-level slice unit (such as the
|
||
root slice <filename>-.slice</filename> or the slice containing all system services
|
||
<filename>system.slice</filename> – see
|
||
<citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry> for
|
||
details on these slice units), plus individual per-service <varname>IPAddressAllow=</varname> lines
|
||
permitting network access to relevant services, and only them.</para>
|
||
|
||
<para>Note that for socket-activated services, the IP access list configured on the socket unit applies to
|
||
all sockets associated with it directly, but not to any sockets created by the ultimately activated services
|
||
for it. Conversely, the IP access list configured for the service is not applied to any sockets passed into
|
||
the service via socket activation. Thus, it is usually a good idea, to replicate the IP access lists on both
|
||
the socket and the service unit, however it often makes sense to maintain one list more open and the other
|
||
one more restricted, depending on the usecase.</para>
|
||
|
||
<para>If these settings are used multiple times in the same unit the specified lists are combined. If an
|
||
empty string is assigned to these settings the specific access list is reset and all previous settings undone.</para>
|
||
|
||
<para>In place of explicit IPv4 or IPv6 address and prefix length specifications a small set of symbolic
|
||
names may be used. The following names are defined:</para>
|
||
|
||
<table>
|
||
<title>Special address/network names</title>
|
||
|
||
<tgroup cols='3'>
|
||
<colspec colname='name'/>
|
||
<colspec colname='definition'/>
|
||
<colspec colname='meaning'/>
|
||
|
||
<thead>
|
||
<row>
|
||
<entry>Symbolic Name</entry>
|
||
<entry>Definition</entry>
|
||
<entry>Meaning</entry>
|
||
</row>
|
||
</thead>
|
||
|
||
<tbody>
|
||
<row>
|
||
<entry><constant>any</constant></entry>
|
||
<entry>0.0.0.0/0 ::/0</entry>
|
||
<entry>Any host</entry>
|
||
</row>
|
||
|
||
<row>
|
||
<entry><constant>localhost</constant></entry>
|
||
<entry>127.0.0.0/8 ::1/128</entry>
|
||
<entry>All addresses on the local loopback</entry>
|
||
</row>
|
||
|
||
<row>
|
||
<entry><constant>link-local</constant></entry>
|
||
<entry>169.254.0.0/16 fe80::/64</entry>
|
||
<entry>All link-local IP addresses</entry>
|
||
</row>
|
||
|
||
<row>
|
||
<entry><constant>multicast</constant></entry>
|
||
<entry>224.0.0.0/4 ff00::/8</entry>
|
||
<entry>All IP multicasting addresses</entry>
|
||
</row>
|
||
</tbody>
|
||
</tgroup>
|
||
</table>
|
||
|
||
<para>Note that these settings might not be supported on some systems (for example if eBPF control group
|
||
support is not enabled in the underlying kernel or container manager). These settings will have no effect in
|
||
that case. If compatibility with such systems is desired it is hence recommended to not exclusively rely on
|
||
them for IP security.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>DeviceAllow=</varname></term>
|
||
|
||
<listitem>
|
||
<para>Control access to specific device nodes by the
|
||
executed processes. Takes two space-separated strings: a
|
||
device node specifier followed by a combination of
|
||
<constant>r</constant>, <constant>w</constant>,
|
||
<constant>m</constant> to control
|
||
<emphasis>r</emphasis>eading, <emphasis>w</emphasis>riting,
|
||
or creation of the specific device node(s) by the unit
|
||
(<emphasis>m</emphasis>knod), respectively. This controls
|
||
the <literal>devices.allow</literal> and
|
||
<literal>devices.deny</literal> control group
|
||
attributes. For details about these control group
|
||
attributes, see <ulink
|
||
url="https://www.kernel.org/doc/Documentation/cgroup-v1/devices.txt">devices.txt</ulink>.</para>
|
||
|
||
<para>The device node specifier is either a path to a device
|
||
node in the file system, starting with
|
||
<filename>/dev/</filename>, or a string starting with either
|
||
<literal>char-</literal> or <literal>block-</literal>
|
||
followed by a device group name, as listed in
|
||
<filename>/proc/devices</filename>. The latter is useful to
|
||
whitelist all current and future devices belonging to a
|
||
specific device group at once. The device group is matched
|
||
according to filename globbing rules, you may hence use the
|
||
<literal>*</literal> and <literal>?</literal>
|
||
wildcards. Examples: <filename>/dev/sda5</filename> is a
|
||
path to a device node, referring to an ATA or SCSI block
|
||
device. <literal>char-pts</literal> and
|
||
<literal>char-alsa</literal> are specifiers for all pseudo
|
||
TTYs and all ALSA sound devices,
|
||
respectively. <literal>char-cpu/*</literal> is a specifier
|
||
matching all CPU related device groups.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>DevicePolicy=auto|closed|strict</varname></term>
|
||
|
||
<listitem>
|
||
<para>
|
||
Control the policy for allowing device access:
|
||
</para>
|
||
<variablelist>
|
||
<varlistentry>
|
||
<term><option>strict</option></term>
|
||
<listitem>
|
||
<para>means to only allow types of access that are
|
||
explicitly specified.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><option>closed</option></term>
|
||
<listitem>
|
||
<para>in addition, allows access to standard pseudo
|
||
devices including
|
||
<filename>/dev/null</filename>,
|
||
<filename>/dev/zero</filename>,
|
||
<filename>/dev/full</filename>,
|
||
<filename>/dev/random</filename>, and
|
||
<filename>/dev/urandom</filename>.
|
||
</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><option>auto</option></term>
|
||
<listitem>
|
||
<para>
|
||
in addition, allows access to all devices if no
|
||
explicit <varname>DeviceAllow=</varname> is present.
|
||
This is the default.
|
||
</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
</variablelist>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>Slice=</varname></term>
|
||
|
||
<listitem>
|
||
<para>The name of the slice unit to place the unit
|
||
in. Defaults to <filename>system.slice</filename> for all
|
||
non-instantiated units of all unit types (except for slice
|
||
units themselves see below). Instance units are by default
|
||
placed in a subslice of <filename>system.slice</filename>
|
||
that is named after the template name.</para>
|
||
|
||
<para>This option may be used to arrange systemd units in a
|
||
hierarchy of slices each of which might have resource
|
||
settings applied.</para>
|
||
|
||
<para>For units of type slice, the only accepted value for
|
||
this setting is the parent slice. Since the name of a slice
|
||
unit implies the parent slice, it is hence redundant to ever
|
||
set this parameter directly for slice units.</para>
|
||
|
||
<para>Special care should be taken when relying on the default slice assignment in templated service units
|
||
that have <varname>DefaultDependencies=no</varname> set, see
|
||
<citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>, section
|
||
"Default Dependencies" for details.</para>
|
||
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>Delegate=</varname></term>
|
||
|
||
<listitem>
|
||
<para>Turns on delegation of further resource control partitioning to processes of the unit. Units where this
|
||
is enabled may create and manage their own private subhierarchy of control groups below the control group of
|
||
the unit itself. For unprivileged services (i.e. those using the <varname>User=</varname> setting) the unit's
|
||
control group will be made accessible to the relevant user. When enabled the service manager will refrain
|
||
from manipulating control groups or moving processes below the unit's control group, so that a clear concept
|
||
of ownership is established: the control group tree above the unit's control group (i.e. towards the root
|
||
control group) is owned and managed by the service manager of the host, while the control group tree below
|
||
the unit's control group is owned and managed by the unit itself. Takes either a boolean argument or a list
|
||
of control group controller names. If true, delegation is turned on, and all supported controllers are
|
||
enabled for the unit, making them available to the unit's processes for management. If false, delegation is
|
||
turned off entirely (and no additional controllers are enabled). If set to a list of controllers, delegation
|
||
is turned on, and the specified controllers are enabled for the unit. Note that additional controllers than
|
||
the ones specified might be made available as well, depending on configuration of the containing slice unit
|
||
or other units contained in it. Note that assigning the empty string will enable delegation, but reset the
|
||
list of controllers, all assignments prior to this will have no effect. Defaults to false.</para>
|
||
|
||
<para>Note that controller delegation to less privileged code is only safe on the unified control group
|
||
hierarchy. Accordingly, access to the specified controllers will not be granted to unprivileged services on
|
||
the legacy hierarchy, even when requested.</para>
|
||
|
||
<para>The following controller names may be specified: <option>cpu</option>, <option>cpuacct</option>,
|
||
<option>io</option>, <option>blkio</option>, <option>memory</option>, <option>devices</option>,
|
||
<option>pids</option>. Not all of these controllers are available on all kernels however, and some are
|
||
specific to the unified hierarchy while others are specific to the legacy hierarchy. Also note that the
|
||
kernel might support further controllers, which aren't covered here yet as delegation is either not supported
|
||
at all for them or not defined cleanly.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
</variablelist>
|
||
</refsect1>
|
||
|
||
<refsect1>
|
||
<title>Deprecated Options</title>
|
||
|
||
<para>The following options are deprecated. Use the indicated superseding options instead:</para>
|
||
|
||
<variablelist class='unit-directives'>
|
||
|
||
<varlistentry>
|
||
<term><varname>CPUShares=<replaceable>weight</replaceable></varname></term>
|
||
<term><varname>StartupCPUShares=<replaceable>weight</replaceable></varname></term>
|
||
|
||
<listitem>
|
||
<para>Assign the specified CPU time share weight to the processes executed. These options take an integer
|
||
value and control the <literal>cpu.shares</literal> control group attribute. The allowed range is 2 to
|
||
262144. Defaults to 1024. For details about this control group attribute, see <ulink
|
||
url="https://www.kernel.org/doc/Documentation/scheduler/sched-design-CFS.txt">sched-design-CFS.txt</ulink>.
|
||
The available CPU time is split up among all units within one slice relative to their CPU time share
|
||
weight.</para>
|
||
|
||
<para>While <varname>StartupCPUShares=</varname> only applies to the startup phase of the system,
|
||
<varname>CPUShares=</varname> applies to normal runtime of the system, and if the former is not set also to
|
||
the startup phase. Using <varname>StartupCPUShares=</varname> allows prioritizing specific services at
|
||
boot-up differently than during normal runtime.</para>
|
||
|
||
<para>Implies <literal>CPUAccounting=true</literal>.</para>
|
||
|
||
<para>These settings are deprecated. Use <varname>CPUWeight=</varname> and
|
||
<varname>StartupCPUWeight=</varname> instead.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>MemoryLimit=<replaceable>bytes</replaceable></varname></term>
|
||
|
||
<listitem>
|
||
<para>Specify the limit on maximum memory usage of the executed processes. The limit specifies how much
|
||
process and kernel memory can be used by tasks in this unit. Takes a memory size in bytes. If the value is
|
||
suffixed with K, M, G or T, the specified memory size is parsed as Kilobytes, Megabytes, Gigabytes, or
|
||
Terabytes (with the base 1024), respectively. Alternatively, a percentage value may be specified, which is
|
||
taken relative to the installed physical memory on the system. If assigned the special value
|
||
<literal>infinity</literal>, no memory limit is applied. This controls the
|
||
<literal>memory.limit_in_bytes</literal> control group attribute. For details about this control group
|
||
attribute, see <ulink
|
||
url="https://www.kernel.org/doc/Documentation/cgroup-v1/memory.txt">memory.txt</ulink>.</para>
|
||
|
||
<para>Implies <literal>MemoryAccounting=true</literal>.</para>
|
||
|
||
<para>This setting is deprecated. Use <varname>MemoryMax=</varname> instead.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>BlockIOAccounting=</varname></term>
|
||
|
||
<listitem>
|
||
<para>Turn on Block I/O accounting for this unit, if the legacy control group hierarchy is used on the
|
||
system. Takes a boolean argument. Note that turning on block I/O accounting for one unit will also implicitly
|
||
turn it on for all units contained in the same slice and all for its parent slices and the units contained
|
||
therein. The system default for this setting may be controlled with
|
||
<varname>DefaultBlockIOAccounting=</varname> in
|
||
<citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
|
||
|
||
<para>This setting is deprecated. Use <varname>IOAccounting=</varname> instead.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>BlockIOWeight=<replaceable>weight</replaceable></varname></term>
|
||
<term><varname>StartupBlockIOWeight=<replaceable>weight</replaceable></varname></term>
|
||
|
||
<listitem><para>Set the default overall block I/O weight for the executed processes, if the legacy control
|
||
group hierarchy is used on the system. Takes a single weight value (between 10 and 1000) to set the default
|
||
block I/O weight. This controls the <literal>blkio.weight</literal> control group attribute, which defaults to
|
||
500. For details about this control group attribute, see <ulink
|
||
url="https://www.kernel.org/doc/Documentation/cgroup-v1/blkio-controller.txt">blkio-controller.txt</ulink>.
|
||
The available I/O bandwidth is split up among all units within one slice relative to their block I/O
|
||
weight.</para>
|
||
|
||
<para>While <varname>StartupBlockIOWeight=</varname> only
|
||
applies to the startup phase of the system,
|
||
<varname>BlockIOWeight=</varname> applies to the later runtime
|
||
of the system, and if the former is not set also to the
|
||
startup phase. This allows prioritizing specific services at
|
||
boot-up differently than during runtime.</para>
|
||
|
||
<para>Implies
|
||
<literal>BlockIOAccounting=true</literal>.</para>
|
||
|
||
<para>These settings are deprecated. Use <varname>IOWeight=</varname> and <varname>StartupIOWeight=</varname>
|
||
instead.</para>
|
||
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>BlockIODeviceWeight=<replaceable>device</replaceable> <replaceable>weight</replaceable></varname></term>
|
||
|
||
<listitem>
|
||
<para>Set the per-device overall block I/O weight for the executed processes, if the legacy control group
|
||
hierarchy is used on the system. Takes a space-separated pair of a file path and a weight value to specify
|
||
the device specific weight value, between 10 and 1000. (Example: "/dev/sda 500"). The file path may be
|
||
specified as path to a block device node or as any other file, in which case the backing block device of the
|
||
file system of the file is determined. This controls the <literal>blkio.weight_device</literal> control group
|
||
attribute, which defaults to 1000. Use this option multiple times to set weights for multiple devices. For
|
||
details about this control group attribute, see <ulink
|
||
url="https://www.kernel.org/doc/Documentation/cgroup-v1/blkio-controller.txt">blkio-controller.txt</ulink>.</para>
|
||
|
||
<para>Implies
|
||
<literal>BlockIOAccounting=true</literal>.</para>
|
||
|
||
<para>This setting is deprecated. Use <varname>IODeviceWeight=</varname> instead.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><varname>BlockIOReadBandwidth=<replaceable>device</replaceable> <replaceable>bytes</replaceable></varname></term>
|
||
<term><varname>BlockIOWriteBandwidth=<replaceable>device</replaceable> <replaceable>bytes</replaceable></varname></term>
|
||
|
||
<listitem>
|
||
<para>Set the per-device overall block I/O bandwidth limit for the executed processes, if the legacy control
|
||
group hierarchy is used on the system. Takes a space-separated pair of a file path and a bandwidth value (in
|
||
bytes per second) to specify the device specific bandwidth. The file path may be a path to a block device
|
||
node, or as any other file in which case the backing block device of the file system of the file is used. If
|
||
the bandwidth is suffixed with K, M, G, or T, the specified bandwidth is parsed as Kilobytes, Megabytes,
|
||
Gigabytes, or Terabytes, respectively, to the base of 1000. (Example:
|
||
"/dev/disk/by-path/pci-0000:00:1f.2-scsi-0:0:0:0 5M"). This controls the
|
||
<literal>blkio.throttle.read_bps_device</literal> and <literal>blkio.throttle.write_bps_device</literal>
|
||
control group attributes. Use this option multiple times to set bandwidth limits for multiple devices. For
|
||
details about these control group attributes, see <ulink
|
||
url="https://www.kernel.org/doc/Documentation/cgroup-v1/blkio-controller.txt">blkio-controller.txt</ulink>.
|
||
</para>
|
||
|
||
<para>Implies
|
||
<literal>BlockIOAccounting=true</literal>.</para>
|
||
|
||
<para>These settings are deprecated. Use <varname>IOReadBandwidthMax=</varname> and
|
||
<varname>IOWriteBandwidthMax=</varname> instead.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
</variablelist>
|
||
</refsect1>
|
||
|
||
<refsect1>
|
||
<title>See Also</title>
|
||
<para>
|
||
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.exec</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
|
||
<citerefentry><refentrytitle>systemd.special</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
|
||
The documentation for control groups and specific controllers in the Linux kernel:
|
||
<ulink url="https://www.kernel.org/doc/Documentation/cgroup-v1/cgroups.txt">cgroups.txt</ulink>,
|
||
<ulink url="https://www.kernel.org/doc/Documentation/cgroup-v1/cpuacct.txt">cpuacct.txt</ulink>,
|
||
<ulink url="https://www.kernel.org/doc/Documentation/cgroup-v1/memory.txt">memory.txt</ulink>,
|
||
<ulink url="https://www.kernel.org/doc/Documentation/cgroup-v1/blkio-controller.txt">blkio-controller.txt</ulink>.
|
||
</para>
|
||
</refsect1>
|
||
</refentry>
|