3802a3d3d7af51ddff31943d5514382f01265770Lennart Poettering<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"

12b42c76672a66c2d4ea7212c14f8f1b5a62b78dTom Gundersen"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek

301af7e4853ad0281402f8d86f5a77c6cb7ce9f4Josh Triplett<refentry id="systemd.resource-control">

301af7e4853ad0281402f8d86f5a77c6cb7ce9f4Josh Triplett <refentryinfo>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <title>systemd.resource-control</title>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <productname>systemd</productname>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <authorgroup>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <author>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <contrib>Developer</contrib>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <firstname>Lennart</firstname>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <surname>Poettering</surname>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <email>lennart@poettering.net</email>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek </author>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek </authorgroup>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek </refentryinfo>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <refmeta>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <refentrytitle>systemd.resource-control</refentrytitle>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <manvolnum>5</manvolnum>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek </refmeta>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <refnamediv>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <refname>systemd.resource-control</refname>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <refpurpose>Resource control unit settings</refpurpose>

301af7e4853ad0281402f8d86f5a77c6cb7ce9f4Josh Triplett </refnamediv>

301af7e4853ad0281402f8d86f5a77c6cb7ce9f4Josh Triplett

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <refsynopsisdiv>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <para>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <filename><replaceable>slice</replaceable>.slice</filename>,

12b42c76672a66c2d4ea7212c14f8f1b5a62b78dTom Gundersen <filename><replaceable>scope</replaceable>.scope</filename>,

12b42c76672a66c2d4ea7212c14f8f1b5a62b78dTom Gundersen <filename><replaceable>service</replaceable>.service</filename>,

301af7e4853ad0281402f8d86f5a77c6cb7ce9f4Josh Triplett <filename><replaceable>socket</replaceable>.socket</filename>,

12b42c76672a66c2d4ea7212c14f8f1b5a62b78dTom Gundersen <filename><replaceable>mount</replaceable>.mount</filename>,

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <filename><replaceable>swap</replaceable>.swap</filename>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek </para>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek </refsynopsisdiv>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <refsect1>

dd2b607b7d1ce355e93f9f71cd256ec20b8ae9c4Thomas Hindoe Paaboel Andersen <title>Description</title>

18ead1b00dff180a97507d014325cb46198e6657Chris Mayo

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <para>Unit configuration files for services, slices, scopes,

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek sockets, mount points, and swap devices share a subset of

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek configuration options for resource control of spawned

e93549ef29c4123d9ee45acb5815048390201e49Zbigniew Jędrzejewski-Szmek processes. Internally, this relies on the Control Groups

301af7e4853ad0281402f8d86f5a77c6cb7ce9f4Josh Triplett kernel concept for organizing processes in a hierarchical tree of

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek named groups for the purpose of resource management.</para>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <para>This man page lists the configuration options shared by

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek those six unit types. See

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek for the common options of all unit configuration files, and

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>,

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <citerefentry><refentrytitle>systemd.scope</refentrytitle><manvolnum>5</manvolnum></citerefentry>,

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>,

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <citerefentry><refentrytitle>systemd.mount</refentrytitle><manvolnum>5</manvolnum></citerefentry>,

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek and

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <citerefentry><refentrytitle>systemd.swap</refentrytitle><manvolnum>5</manvolnum></citerefentry>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek for more information on the specific unit configuration files. The

8d0e0ddda6501479eb69164687c83c1a7667b33aJan Engelhardt resource control configuration options are configured in the

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek [Slice], [Scope], [Service], [Socket], [Mount], or [Swap]

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek sections, depending on the unit type.</para>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <para>See the <ulink

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek url="http://www.freedesktop.org/wiki/Software/systemd/ControlGroupInterface/">New

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek Control Group Interfaces</ulink> for an introduction on how to make

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek use of resource control APIs from programs.</para>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek </refsect1>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <refsect1>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <title>Automatic Dependencies</title>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <para>Units with the <varname>Slice=</varname> setting set get

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek automatic <varname>Requires=</varname> and

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <varname>After=</varname> dependencies on the specified slice

8c9571d0ae50656f730a5e37378d5c3dcf3b9789Lennart Poettering unit.</para>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek </refsect1>

442f7f155358a7396a350d3c47ea42e86bee4024Chris Atkinson

a8eaaee72a2f06e0fb64fb71de3b71ecba31dafbJan Engelhardt <refsect1>

8c9571d0ae50656f730a5e37378d5c3dcf3b9789Lennart Poettering <title>Options</title>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <para>Units of the types listed above can have settings

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek for resource control configuration:</para>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <variablelist class='unit-directives'>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <varlistentry>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <term><varname>CPUAccounting=</varname></term>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <listitem>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <para>Turn on CPU usage accounting for this unit. Takes a

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek boolean argument. Note that turning on CPU accounting for

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek one unit will also implicitly turn it on for all units

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek contained in the same slice and for all its parent slices

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek and the units contained therein. The system default for this

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek setting may be controlled with

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <varname>DefaultCPUAccounting=</varname> in

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek </listitem>

0dc5d23c85db85f96b141d4d32deee8018e56a6aLennart Poettering </varlistentry>

0dc5d23c85db85f96b141d4d32deee8018e56a6aLennart Poettering

0dc5d23c85db85f96b141d4d32deee8018e56a6aLennart Poettering <varlistentry>

0dc5d23c85db85f96b141d4d32deee8018e56a6aLennart Poettering <term><varname>CPUShares=<replaceable>weight</replaceable></varname></term>

0dc5d23c85db85f96b141d4d32deee8018e56a6aLennart Poettering <term><varname>StartupCPUShares=<replaceable>weight</replaceable></varname></term>

0dc5d23c85db85f96b141d4d32deee8018e56a6aLennart Poettering

0dc5d23c85db85f96b141d4d32deee8018e56a6aLennart Poettering <listitem>

0dc5d23c85db85f96b141d4d32deee8018e56a6aLennart Poettering <para>Assign the specified CPU time share weight to the

0dc5d23c85db85f96b141d4d32deee8018e56a6aLennart Poettering processes executed. These options take an integer value and

0dc5d23c85db85f96b141d4d32deee8018e56a6aLennart Poettering control the <literal>cpu.shares</literal> control group

0dc5d23c85db85f96b141d4d32deee8018e56a6aLennart Poettering attribute. The allowed range is 2 to 262144. Defaults to

0dc5d23c85db85f96b141d4d32deee8018e56a6aLennart Poettering 1024. For details about this control group attribute, see

0dc5d23c85db85f96b141d4d32deee8018e56a6aLennart Poettering <ulink

0dc5d23c85db85f96b141d4d32deee8018e56a6aLennart Poettering url="https://www.kernel.org/doc/Documentation/scheduler/sched-design-CFS.txt">sched-design-CFS.txt</ulink>.

cbfaff65cb086e3eb3709cf86dcf63b46622389bKarel Zak The available CPU time is split up among all units within

5470c03b37d8421a903564c2c8028c8b8d67d403Lennart Poettering one slice relative to their CPU time share weight.</para>

b938cb902c3b5bca807a94b277672c64d6767886Jan Engelhardt

5470c03b37d8421a903564c2c8028c8b8d67d403Lennart Poettering <para>While <varname>StartupCPUShares=</varname> only

0dc5d23c85db85f96b141d4d32deee8018e56a6aLennart Poettering applies to the startup phase of the system,

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <varname>CPUShares=</varname> applies to normal runtime of

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek the system, and if the former is not set also to the startup

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek phase. Using <varname>StartupCPUShares=</varname> allows

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek prioritizing specific services at boot-up differently than

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek during normal runtime.</para>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <para>These options imply

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <literal>CPUAccounting=true</literal>.</para>

0dc5d23c85db85f96b141d4d32deee8018e56a6aLennart Poettering </listitem>

0dc5d23c85db85f96b141d4d32deee8018e56a6aLennart Poettering </varlistentry>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <varlistentry>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek <term><varname>CPUQuota=</varname></term>

3cc765d2718ac9b4ff978044ceabf5ad59d73edfZbigniew Jędrzejewski-Szmek

<listitem>

<para>Assign the specified CPU time quota to the processes

executed. Takes a percentage value, suffixed with "%". The

percentage specifies how much CPU time the unit shall get at

maximum, relative to the total CPU time available on one

CPU. Use values &gt; 100% for allotting CPU time on more than

one CPU. This controls the

<literal>cpu.cfs_quota_us</literal> control group

attribute. 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>.</para>

<para>Example: <varname>CPUQuota=20%</varname> ensures that

the executed processes will never get more than 20% CPU time

on one CPU.</para>

<para>Implies <literal>CPUAccounting=true</literal>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>MemoryAccounting=</varname></term>

<listitem>

<para>Turn on process and kernel memory accounting for this

unit. Takes a boolean argument. Note that turning on memory

accounting for one unit will also implicitly turn it on for

all units contained in the same slice and for all its parent

slices and the units contained therein. The system default

for this setting may be controlled with

<varname>DefaultMemoryAccounting=</varname> in

<citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</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. 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/cgroups/memory.txt">memory.txt</ulink>.</para>

<para>Implies <literal>MemoryAccounting=true</literal>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>TasksAccounting=</varname></term>

<listitem>

<para>Turn on task accounting for this unit. Takes a

boolean argument. If enabled, the system manager will keep

track of the number of tasks in the unit. The number of

tasks accounted this way includes both kernel threads and

userspace processes, with each thread counting

individually. Note that turning on tasks accounting for one

unit will also implicitly turn it on for all units contained

in the same slice and for all its parent slices and the

units contained therein. The system default for this setting

may be controlled with

<varname>DefaultTasksAccounting=</varname> in

<citerefentry><refentrytitle>systemd-system.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>TasksMax=<replaceable>N</replaceable></varname></term>

<listitem>

<para>Specify the maximum number of tasks that may be

created in the unit. This ensures that the number of tasks

accounted for the unit (see above) stays below a specific

limit. If assigned the special value

<literal>infinity</literal>, no tasks limit is applied. This

controls the <literal>pids.max</literal> control group

attribute. For details about this control group attribute,

see <ulink

url="https://www.kernel.org/doc/Documentation/cgroups/pids.txt">pids.txt</ulink>.</para>

<para>Implies <literal>TasksAccounting=true</literal>. The

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>

<varlistentry>

<term><varname>BlockIOAccounting=</varname></term>

<listitem>

<para>Turn on Block I/O accounting for this unit. 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>

</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. 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/cgroups/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>

</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. 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/cgroups/blkio-controller.txt">blkio-controller.txt</ulink>.</para>

<para>Implies

<literal>BlockIOAccounting=true</literal>.</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. 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.read_bps_device</literal> and

<literal>blkio.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/cgroups/blkio-controller.txt">blkio-controller.txt</ulink>.

</para>

<para>Implies

<literal>BlockIOAccounting=true</literal>.</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/cgroups/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 file name 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>NetClass=</varname></term>

<listitem><para>Configures a network class number to assign to the

unit. This value will be set to the

<literal>net_cls.class_id</literal> property of the

<literal>net_cls</literal> cgroup of the unit. The directive

accepts a numerical value (for fixed number assignment) and the keyword

<literal>auto</literal> (for dynamic allocation). Network traffic of

all processes inside the unit will have the network class ID assigned

by the kernel. Also see

the kernel docs for

<ulink url="https://www.kernel.org/doc/Documentation/cgroups/net_cls.txt">net_cls controller</ulink>

and

<citerefentry><refentrytitle>systemd.resource-control</refentrytitle><manvolnum>5</manvolnum></citerefentry>.

</para></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>

</listitem>

</varlistentry>

<varlistentry>

<term><varname>Delegate=</varname></term>

<listitem>

<para>Turns on delegation of further resource control

partitioning to processes of the unit. For unprivileged

services (i.e. those using the <varname>User=</varname>

setting), this allows processes to create a subhierarchy

beneath its control group path. For privileged services and

scopes, this ensures the processes will have all control

group controllers enabled.</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.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/cgroups/cgroups.txt">cgroups.txt</ulink>,

<ulink url="https://www.kernel.org/doc/Documentation/cgroups/cpuacct.txt">cpuacct.txt</ulink>,

<ulink url="https://www.kernel.org/doc/Documentation/cgroups/memory.txt">memory.txt</ulink>,

<ulink url="https://www.kernel.org/doc/Documentation/cgroups/blkio-controller.txt">blkio-controller.txt</ulink>.

</para>

</refsect1>

</refentry>