3 <!DOCTYPE refentry PUBLIC
"-//OASIS//DTD DocBook XML V4.5//EN"
4 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
5 <!-- SPDX-License-Identifier: LGPL-2.1+ -->
6 <refentry id=
"systemd-sysctl.service"
7 xmlns:
xi=
"http://www.w3.org/2001/XInclude">
10 <title>systemd-sysctl.service
</title>
11 <productname>systemd
</productname>
15 <refentrytitle>systemd-sysctl.service
</refentrytitle>
16 <manvolnum>8</manvolnum>
20 <refname>systemd-sysctl.service
</refname>
21 <refname>systemd-sysctl
</refname>
22 <refpurpose>Configure kernel parameters at boot
</refpurpose>
27 <command>/usr/lib/systemd/systemd-sysctl
</command>
28 <arg choice=
"opt" rep=
"repeat">OPTIONS
</arg>
29 <arg choice=
"opt" rep=
"repeat"><replaceable>CONFIGFILE
</replaceable></arg>
31 <para><filename>systemd-sysctl.service
</filename></para>
35 <title>Description
</title>
37 <para><filename>systemd-sysctl.service
</filename> is an early boot
38 service that configures
39 <citerefentry project='man-pages'
><refentrytitle>sysctl
</refentrytitle><manvolnum>8</manvolnum></citerefentry>
40 kernel parameters by invoking
<command>/usr/lib/systemd/systemd-sysctl
</command>.
</para>
42 <para>When invoked with no arguments,
<command>/usr/lib/systemd/systemd-sysctl
</command> applies
43 all directives from configuration files listed in
44 <citerefentry><refentrytitle>sysctl.d
</refentrytitle><manvolnum>5</manvolnum></citerefentry>.
45 If one or more filenames are passed on the command line, only the directives in these files are
48 <para>In addition,
<option>--prefix=
</option> option may be used to limit which sysctl
49 settings are applied.
</para>
52 <citerefentry><refentrytitle>sysctl.d
</refentrytitle><manvolnum>5</manvolnum></citerefentry>
53 for information about the configuration of sysctl settings. After sysctl configuration is
54 changed on disk, it must be written to the files in
<filename>/proc/sys
</filename> before it
55 takes effect. It is possible to update specific settings, or simply to reload all configuration,
56 see Examples below.
</para>
59 <refsect1><title>Options
</title>
61 <varlistentry id='prefix'
>
62 <term><option>--prefix=
</option></term>
64 <para>Only apply rules with the specified prefix.
</para>
68 <xi:include href=
"standard-options.xml" xpointer=
"cat-config" />
69 <xi:include href=
"standard-options.xml" xpointer=
"no-pager" />
70 <xi:include href=
"standard-options.xml" xpointer=
"help" />
71 <xi:include href=
"standard-options.xml" xpointer=
"version" />
77 <title>Examples
</title>
80 <title>Reset all sysctl settings
</title>
82 <programlisting>systemctl restart systemd-sysctl
</programlisting>
86 <title>View coredump handler configuration
</title>
88 <programlisting># sysctl kernel.core_pattern
89 kernel.core_pattern = |/usr/libexec/abrt-hook-ccpp %s %c %p %u %g %t %P %I
94 <title>Update coredump handler configuration
</title>
96 <programlisting># /usr/lib/systemd/systemd-sysctl --prefix kernel.core_pattern
</programlisting>
98 <para>This searches all the directories listed in
99 <citerefentry><refentrytitle>sysctl.d
</refentrytitle><manvolnum>5</manvolnum></citerefentry>
100 for configuration files and writes
<filename>/proc/sys/kernel/core_pattern
</filename>.
</para>
104 <title>Update coredump handler configuration according to a specific file
</title>
106 <programlisting># /usr/lib/systemd/systemd-sysctl
50-coredump.conf
</programlisting>
108 <para>This applies all the settings found in
<filename>50-coredump.conf
</filename>.
109 Either
<filename>/etc/sysctl.d/
50-coredump.conf
</filename>, or
110 <filename>/run/sysctl.d/
50-coredump.conf
</filename>, or
111 <filename>/usr/lib/sysctl.d/
50-coredump.conf
</filename> will be used, in the order
112 of preference.
</para>
116 <citerefentry project='man-pages'
><refentrytitle>sysctl
</refentrytitle><manvolnum>8</manvolnum></citerefentry>
117 for various ways to directly apply sysctl settings.
</para>
121 <title>See Also
</title>
123 <citerefentry><refentrytitle>systemd
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
124 <citerefentry><refentrytitle>sysctl.d
</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
125 <citerefentry project='man-pages'
><refentrytitle>sysctl
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,