<?xml version="1.0"?> <!--*-nxml-*--> <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> <!-- This file is part of systemd. Copyright 2012 Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. --> <refentry id="systemd-sysctl.service" xmlns:xi="http://www.w3.org/2001/XInclude"> <refentryinfo> <title>systemd-sysctl.service</title> <productname>systemd</productname> <authorgroup> <author> <contrib>Developer</contrib> <firstname>Lennart</firstname> <surname>Poettering</surname> <email>lennart@poettering.net</email> </author> </authorgroup> </refentryinfo> <refmeta> <refentrytitle>systemd-sysctl.service</refentrytitle> <manvolnum>8</manvolnum> </refmeta> <refnamediv> <refname>systemd-sysctl.service</refname> <refname>systemd-sysctl</refname> <refpurpose>Configure kernel parameters at boot</refpurpose> </refnamediv> <refsynopsisdiv> <cmdsynopsis> <command>/usr/lib/systemd/systemd-sysctl</command> <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="opt" rep="repeat"><replaceable>CONFIGFILE</replaceable></arg> </cmdsynopsis> <para><filename>systemd-sysctl.service</filename></para> </refsynopsisdiv> <refsect1> <title>Description</title> <para><filename>systemd-sysctl.service</filename> is an early boot service that configures <citerefentry project='man-pages'><refentrytitle>sysctl</refentrytitle><manvolnum>8</manvolnum></citerefentry> kernel parameters by invoking <command>/usr/lib/systemd/systemd-sysctl</command>.</para> <para>When invoked with no arguments, <command>/usr/lib/systemd/systemd-sysctl</command> applies all directives from configuration files listed in <citerefentry><refentrytitle>sysctl.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>. If one or more filenames are passed on the command line, only the directives in these files are applied.</para> <para>In addition, <option>--prefix=</option> option may be used to limit which sysctl settings are applied.</para> <para>See <citerefentry project='man-pages'><refentrytitle>sysctl.d</refentrytitle><manvolnum>5</manvolnum></citerefentry> for information about the configuration of sysctl settings. After sysctl configuration is changed on disk, it must be written to the files in <filename>/proc/sys</filename> before it takes effect. It is possible to update specific settings, or simply to reload all configuration, see Examples below.</para> </refsect1> <refsect1><title>Options</title> <variablelist> <varlistentry id='prefix'> <term><option>--prefix=</option></term> <listitem> <para>Only apply rules with the specified prefix.</para> </listitem> </varlistentry> <xi:include href="standard-options.xml" xpointer="help" /> <xi:include href="standard-options.xml" xpointer="version" /> </variablelist> </refsect1> <refsect1> <title>Examples</title> <example> <title>Reset all sysctl settings</title> <programlisting>systemctl restart systemd-sysctl</programlisting> </example> <example> <title>View coredump handler configuration</title> <programlisting># sysctl kernel.core_pattern kernel.core_pattern = |/usr/libexec/abrt-hook-ccpp %s %c %p %u %g %t %P %I </programlisting> </example> <example> <title>Update coredump handler configuration</title> <programlisting># /usr/lib/systemd/systemd-sysctl --prefix kernel.core_pattern</programlisting> <para>This searches all the directories listed in <citerefentry><refentrytitle>sysctl.d</refentrytitle><manvolnum>5</manvolnum></citerefentry> for configuration files and writes <filename>/proc/sys/kernel/core_pattern</filename>.</para> </example> <example> <title>Update coredump handler configuration according to a specific file</title> <programlisting># /usr/lib/systemd/systemd-sysctl 50-coredump.conf</programlisting> <para>This applies all the settings found in <filename>50-coredump.conf</filename>. Either <filename>/etc/sysctl.d/50-coredump.conf</filename>, or <filename>/run/sysctl.d/50-coredump.conf</filename>, or <filename>/usr/lib/sysctl.d/50-coredump.conf</filename> will be used, in the order of preference.</para> </example> <para>See <citerefentry project='man-pages'><refentrytitle>sysctl</refentrytitle><manvolnum>8</manvolnum></citerefentry> for various ways to directly apply sysctl settings.</para> </refsect1> <refsect1> <title>See Also</title> <para> <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, <citerefentry project='man-pages'><refentrytitle>sysctl.d</refentrytitle><manvolnum>5</manvolnum></citerefentry>, <citerefentry project='man-pages'><refentrytitle>sysctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>, </para> </refsect1> </refentry>