systemd/man/systemd-udevd.service.xml
Lennart Poettering 818bf54632 tree-wide: drop 'This file is part of systemd' blurb
This part of the copyright blurb stems from the GPL use recommendations:

https://www.gnu.org/licenses/gpl-howto.en.html

The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.

hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
2018-06-14 10:20:20 +02:00

197 lines
7.1 KiB
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<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
<!--
SPDX-License-Identifier: LGPL-2.1+
Copyright 2010-2013 Kay Sievers
-->
<refentry id="systemd-udevd.service"
xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
<title>systemd-udevd.service</title>
<productname>systemd</productname>
<authorgroup>
<author>
<contrib>Developer</contrib>
<firstname>Kay</firstname>
<surname>Sievers</surname>
<email>kay@vrfy.org</email>
</author>
</authorgroup>
</refentryinfo>
<refmeta>
<refentrytitle>systemd-udevd.service</refentrytitle>
<manvolnum>8</manvolnum>
</refmeta>
<refnamediv>
<refname>systemd-udevd.service</refname>
<refname>systemd-udevd-control.socket</refname>
<refname>systemd-udevd-kernel.socket</refname>
<refname>systemd-udevd</refname>
<refpurpose>Device event managing daemon</refpurpose>
</refnamediv>
<refsynopsisdiv>
<para><filename>systemd-udevd.service</filename></para>
<para><filename>systemd-udevd-control.socket</filename></para>
<para><filename>systemd-udevd-kernel.socket</filename></para>
<cmdsynopsis>
<command>/usr/lib/systemd/systemd-udevd</command>
<arg><option>--daemon</option></arg>
<arg><option>--debug</option></arg>
<arg><option>--children-max=</option></arg>
<arg><option>--exec-delay=</option></arg>
<arg><option>--event-timeout=</option></arg>
<arg><option>--resolve-names=early|late|never</option></arg>
<arg><option>--version</option></arg>
<arg><option>--help</option></arg>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1><title>Description</title>
<para><command>systemd-udevd</command> listens to kernel uevents.
For every event, systemd-udevd executes matching instructions
specified in udev rules. See <citerefentry>
<refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum>
</citerefentry>.</para>
<para>The behavior of the daemon can be configured using
<citerefentry><refentrytitle>udev.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
its command line options, environment variables, and on the kernel
command line, or changed dynamically with <command>udevadm
control</command>.
</para>
</refsect1>
<refsect1><title>Options</title>
<variablelist>
<varlistentry>
<term><option>-d</option></term>
<term><option>--daemon</option></term>
<listitem>
<para>Detach and run in the background.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>-D</option></term>
<term><option>--debug</option></term>
<listitem>
<para>Print debug messages to standard error.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>-c=</option></term>
<term><option>--children-max=</option></term>
<listitem>
<para>Limit the number of events executed in parallel.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>-e=</option></term>
<term><option>--exec-delay=</option></term>
<listitem>
<para>Delay the execution of <varname>RUN</varname>
instructions by the given number of seconds. This option
might be useful when debugging system crashes during
coldplug caused by loading non-working kernel
modules.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>-t=</option></term>
<term><option>--event-timeout=</option></term>
<listitem>
<para>Set the number of seconds to wait for events to finish. After
this time, the event will be terminated. The default is 180 seconds.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>-N=</option></term>
<term><option>--resolve-names=</option></term>
<listitem>
<para>Specify when systemd-udevd should resolve names of users and groups.
When set to <option>early</option> (the default), names will be
resolved when the rules are parsed. When set to
<option>late</option>, names will be resolved for every event.
When set to <option>never</option>, names will never be resolved
and all devices will be owned by root.</para>
</listitem>
</varlistentry>
<xi:include href="standard-options.xml" xpointer="help" />
<xi:include href="standard-options.xml" xpointer="version" />
</variablelist>
</refsect1>
<refsect1><title>Kernel command line</title>
<variablelist class='kernel-commandline-options'>
<para>Parameters starting with "rd." will be read when
<command>systemd-udevd</command> is used in an initrd.</para>
<varlistentry>
<term><varname>udev.log_priority=</varname></term>
<term><varname>rd.udev.log_priority=</varname></term>
<listitem>
<para>Set the log level.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>udev.children_max=</varname></term>
<term><varname>rd.udev.children_max=</varname></term>
<listitem>
<para>Limit the number of events executed in parallel.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>udev.exec_delay=</varname></term>
<term><varname>rd.udev.exec_delay=</varname></term>
<listitem>
<para>Delay the execution of <varname>RUN</varname> instructions by the given
number of seconds. This option might be useful when
debugging system crashes during coldplug caused by loading
non-working kernel modules.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>udev.event_timeout=</varname></term>
<term><varname>rd.udev.event_timeout=</varname></term>
<listitem>
<para>Wait for events to finish up to the given number
of seconds. This option might be useful if events are
terminated due to kernel drivers taking too long to initialize.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><varname>net.ifnames=</varname></term>
<listitem>
<para>Network interfaces are renamed to give them predictable names
when possible. It is enabled by default; specifying 0 disables it.</para>
</listitem>
</varlistentry>
</variablelist>
<!-- when adding entries here, consider also adding them
in kernel-command-line.xml -->
</refsect1>
<refsect1>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>udev.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
<citerefentry><refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
<citerefentry><refentrytitle>udevadm</refentrytitle><manvolnum>8</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>