mirror of
https://github.com/systemd/systemd.git
synced 2024-11-28 21:03:52 +08:00
74 lines
4.4 KiB
XML
74 lines
4.4 KiB
XML
<?xml version="1.0"?>
|
|
<!DOCTYPE refsection PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
|
|
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
|
|
|
|
<!--
|
|
SPDX-License-Identifier: LGPL-2.1+
|
|
Copyright © 2014 Josh Triplett
|
|
-->
|
|
|
|
<refsection>
|
|
<refsection id='confd'>
|
|
<title>Configuration Directories and Precedence</title>
|
|
|
|
<para>Configuration files are read from directories in <filename>/etc/</filename>,
|
|
<filename>/run/</filename>, <filename>/usr/local/lib/</filename>, and <filename>/usr/lib/</filename>, in
|
|
order of precedence, as listed in the SYNOPSIS section above. Files must have the
|
|
<literal>.conf</literal> extension. Files in <filename>/etc/</filename> override files with the same name
|
|
in <filename>/run/</filename>, <filename>/usr/local/lib/</filename>, and
|
|
<filename>/usr/lib/</filename>. Files in <filename>/run/</filename> override files with the same name
|
|
under <filename>/usr/</filename>.</para>
|
|
|
|
<para>All configuration files are sorted by their filename in lexicographic order, regardless of which of
|
|
the directories they reside in. If multiple files specify the same option, the entry in the file with the
|
|
lexicographically latest name will take precedence. Thus, the configuration in a certain file may either
|
|
be replaced completely (by placing a file with the same name in a directory with higher priority), or
|
|
individual settings might be changed (by specifying additional settings in a file with a different name
|
|
that is ordered later).</para>
|
|
|
|
<para>Packages should install their configuration files in <filename>/usr/lib/</filename> (distribution
|
|
packages) or <filename>/usr/local/lib/</filename> (local installs). Files in <filename>/etc/</filename>
|
|
are reserved for the local administrator, who may use this logic to override the configuration files
|
|
installed by vendor packages. It is recommended to prefix all filenames with a two-digit number and a
|
|
dash, to simplify the ordering of the files.</para>
|
|
|
|
<para>If the administrator wants to disable a configuration file supplied by the vendor, the recommended
|
|
way is to place a symlink to <filename>/dev/null</filename> in the configuration directory in
|
|
<filename>/etc/</filename>, with the same filename as the vendor configuration file. If the vendor
|
|
configuration file is included in the initrd image, the image has to be regenerated.</para>
|
|
</refsection>
|
|
|
|
<refsection id='main-conf'>
|
|
<title>Configuration Directories and Precedence</title>
|
|
|
|
<para>The default configuration is defined during compilation, so a
|
|
configuration file is only needed when it is necessary to deviate
|
|
from those defaults. By default, the configuration file in
|
|
<filename>/etc/systemd/</filename> contains commented out entries
|
|
showing the defaults as a guide to the administrator. This file
|
|
can be edited to create local overrides.
|
|
</para>
|
|
|
|
<para>When packages need to customize the configuration, they can install configuration snippets in
|
|
<filename>/usr/lib/systemd/*.conf.d/</filename> or <filename>/usr/local/lib/systemd/*.conf.d/</filename>.
|
|
The main configuration file is read before any of the configuration directories, and has the lowest
|
|
precedence; entries in a file in any configuration directory override entries in the single configuration
|
|
file. Files in the <filename>*.conf.d/</filename> configuration subdirectories are sorted by their
|
|
filename in lexicographic order, regardless of in which of the subdirectories they reside. When multiple
|
|
files specify the same option, for options which accept just a single value, the entry in the file with
|
|
the lexicographically latest name takes precedence. For options which accept a list of values, entries
|
|
are collected as they occur in files sorted lexicographically.</para>
|
|
|
|
<para>Files in <filename>/etc/</filename> are reserved for the local administrator, who may use this
|
|
logic to override the configuration files installed by vendor packages. It is recommended to prefix all
|
|
filenames in those subdirectories with a two-digit number and a dash, to simplify the ordering of the
|
|
files.</para>
|
|
|
|
<para>To disable a configuration file supplied by the vendor, the
|
|
recommended way is to place a symlink to
|
|
<filename>/dev/null</filename> in the configuration directory in
|
|
<filename>/etc/</filename>, with the same filename as the vendor
|
|
configuration file.</para>
|
|
</refsection>
|
|
</refsection>
|