systemd/man/sysctl.d.xml

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  Copyright 2011 Lennart Poettering

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<refentry id="sysctl.d">

        <refentryinfo>
                <title>sysctl.d</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>sysctl.d</refentrytitle>
                <manvolnum>5</manvolnum>
        </refmeta>

        <refnamediv>
                <refname>sysctl.d</refname>
                <refpurpose>Configure kernel parameters at boot</refpurpose>
        </refnamediv>

        <refsynopsisdiv>
                <para><filename>/usr/lib/sysctl.d/*.conf</filename></para>
                <para><filename>/etc/sysctl.d/*.conf</filename></para>
                <para><filename>/run/sysctl.d/*.conf</filename></para>
        </refsynopsisdiv>

        <refsect1>
                <title>Description</title>

		<para><command>systemd</command> uses
		<filename>/etc/sysctl.d/</filename> to configure
		<citerefentry><refentrytitle>sysctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>
		kernel parameters to load during boot. Each
		configuration file is named in the style of
		<filename>/etc/sysctl.d/&lt;program&gt;.conf</filename>.</para>
        </refsect1>

        <refsect1>
		<title>Configuration Format</title>

		<para>The configuration files should simply contain a
		list of variable assignments, separated by
		newlines. Empty lines and lines whose first
		non-whitespace character is # or ; are ignored.</para>

                <para>Note that both / and . are accepted as
                separators in sysctl variable names.</para>

                <para>Files in <filename>/etc/</filename> overwrite
                files with the same name in <filename>/usr/lib/</filename>.
                Files in <filename>/run</filename> overwrite files with
                the same name in <filename>/etc/</filename> and
                <filename>/usr/lib/</filename>. Packages should install their
                configuration files in <filename>/usr/lib/</filename>, files
                in <filename>/etc/</filename> are reserved for the local
                administration, which possibly decides to overwrite the
                configurations installed from packages. All files are sorted
                by filename in alphabetical order, regardless in which of the
                directories they reside, to ensure that a specific
                configuration file takes precedence over another file with
                an alphabetically later name.</para>
        </refsect1>

        <refsect1>
                <title>Example</title>
                <example>
                        <title>/etc/sysctl.d/domain-name.conf example:</title>

                        <programlisting># Set kernel YP domain name
kernel.domainname=example.com</programlisting>
                </example>
        </refsect1>

        <refsect1>
                <title>See Also</title>
                <para>
                        <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
                        <citerefentry><refentrytitle>sysctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
                        <citerefentry><refentrytitle>sysctl.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
                </para>
        </refsect1>

</refentry>