1<?xml version='1.0'?>
2<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
3  "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
4<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
5
6<refentry id="udev.conf"
7          xmlns:xi="http://www.w3.org/2001/XInclude">
8
9  <refentryinfo>
10    <title>udev.conf</title>
11    <productname>systemd</productname>
12  </refentryinfo>
13
14  <refmeta>
15    <refentrytitle>udev.conf</refentrytitle>
16    <manvolnum>5</manvolnum>
17  </refmeta>
18
19  <refnamediv>
20    <refname>udev.conf</refname>
21    <refpurpose>Configuration for device event managing daemon</refpurpose>
22  </refnamediv>
23
24  <refsynopsisdiv>
25    <para><filename>/etc/udev/udev.conf</filename></para>
26  </refsynopsisdiv>
27
28  <refsect1>
29    <title>Description</title>
30
31    <para>
32      <citerefentry><refentrytitle>systemd-udevd</refentrytitle><manvolnum>8</manvolnum></citerefentry>
33      expects its main configuration file at
34      <filename>/etc/udev/udev.conf</filename>. It consists of a set
35      of variables allowing the user to override default udev
36      values. All empty lines or lines beginning with '#' are
37      ignored. The following variables can be set:
38    </para>
39
40    <variablelist class='config-directives'>
41      <varlistentry>
42        <term><varname>udev_log=</varname></term>
43
44        <listitem>
45          <para>The log level. Valid values are the numerical
46          syslog priorities or their textual representations:
47          <option>err</option>, <option>info</option> and
48          <option>debug</option>.</para>
49        </listitem>
50      </varlistentry>
51
52      <varlistentry>
53        <term><varname>children_max=</varname></term>
54
55        <listitem>
56          <para>An integer. The maximum number of events executed in parallel.</para>
57
58          <para>This is the same as the <option>--children-max=</option> option.</para>
59        </listitem>
60      </varlistentry>
61
62      <varlistentry>
63        <term><varname>exec_delay=</varname></term>
64
65        <listitem>
66          <para>An integer. Delay the execution of each <varname>RUN{<replaceable>program</replaceable>}</varname>
67          parameter by the given number of seconds. This option
68          might be useful when debugging system crashes during
69          coldplug caused by loading non-working kernel
70          modules.</para>
71
72          <para>This is the same as the <option>--exec-delay=</option> option.</para>
73        </listitem>
74      </varlistentry>
75
76      <varlistentry>
77        <term><varname>event_timeout=</varname></term>
78
79        <listitem>
80          <para>An integer. The number of seconds to wait for events to finish. After
81          this time, the event will be terminated. The default is 180 seconds.</para>
82
83          <para>This is the same as the <option>--event-timeout=</option> option.</para>
84        </listitem>
85      </varlistentry>
86
87      <varlistentry>
88        <term><varname>resolve_names=</varname></term>
89
90        <listitem>
91          <para>Specifies when systemd-udevd should resolve names of users and groups.  When set to
92          <option>early</option> (the default), names will be resolved when the rules are parsed.
93          When set to <option>late</option>, names will be resolved for every event.  When set to
94          <option>never</option>, names will never be resolved and all devices will be owned by
95          root.</para>
96
97          <para>This is the same as the <option>--resolve-names=</option> option.</para>
98        </listitem>
99      </varlistentry>
100
101      <varlistentry>
102        <term><varname>timeout_signal=</varname></term>
103
104        <listitem>
105          <para>Specifies a signal that <filename>systemd-udevd</filename> will send on worker
106          timeouts. Note that both workers and spawned processes will be killed using this
107          signal. Defaults to <option>SIGKILL</option>.</para>
108        </listitem>
109      </varlistentry>
110    </variablelist>
111
112    <para>
113      In addition, <filename>systemd-udevd</filename> can be configured
114      by command line options and the kernel command line (see
115      <citerefentry><refentrytitle>systemd-udevd</refentrytitle><manvolnum>8</manvolnum></citerefentry>).
116    </para>
117  </refsect1>
118
119  <refsect1>
120    <title>See Also</title>
121    <para>
122      <citerefentry><refentrytitle>systemd-udevd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
123      <citerefentry><refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
124      <citerefentry><refentrytitle>udevadm</refentrytitle><manvolnum>8</manvolnum></citerefentry>
125    </para>
126  </refsect1>
127</refentry>
128