<?xml version='1.0'?> <?xml-stylesheet type="text/xsl" href="http://docbook.sourceforge.net/release/xsl/current/xhtml/docbook.xsl"?> <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> <refentry id="udevd"> <refentryinfo> <title>udevd</title> <productname>udev</productname> </refentryinfo> <refmeta> <refentrytitle>udevd</refentrytitle> <manvolnum>8</manvolnum> <refmiscinfo class="version"></refmiscinfo> </refmeta> <refnamediv> <refname>udevd</refname><refpurpose>event managing daemon</refpurpose> </refnamediv> <refsynopsisdiv> <cmdsynopsis> <command>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>--resolve-names=early|late|never</option></arg> <arg><option>--version</option></arg> <arg><option>--help</option></arg> </cmdsynopsis> </refsynopsisdiv> <refsect1><title>Description</title> <para>udevd listens to kernel uevents. For every event, udevd executes matching instructions specified in udev rules. See <citerefentry> <refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum> </citerefentry>.</para> <para>On startup the content of the directory <filename>/lib/udev/devices</filename> is copied to <filename>/dev</filename>. If kernel modules specify static device nodes, these nodes are created even without a corresponding kernel device, to allow on-demand loading of kernel modules. Matching permissions specified in udev rules are applied to these static device nodes.</para> <para>The behavior of the running daemon can be changed with <command>udevadm control</command>.</para> </refsect1> <refsect1><title>Options</title> <variablelist> <varlistentry> <term><option>--daemon</option></term> <listitem> <para>Detach and run in the background.</para> </listitem> </varlistentry> <varlistentry> <term><option>--debug</option></term> <listitem> <para>Print debug messages to stderr.</para> </listitem> </varlistentry> <varlistentry> <term><option>--children-max=</option></term> <listitem> <para>Limit the number of parallel executed events.</para> </listitem> </varlistentry> <varlistentry> <term><option>--exec-delay=</option></term> <listitem> <para>Number of seconds to delay the execution of RUN instructions. This might be useful when debugging system crashes during coldplug cause by loading non-working kernel modules.</para> </listitem> </varlistentry> <varlistentry> <term><option>--resolve-names=</option></term> <listitem> <para>Specify when 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> <varlistentry> <term><option>--version</option></term> <listitem> <para>Print version number.</para> </listitem> </varlistentry> <varlistentry> <term><option>--help</option></term> <listitem> <para>Print help text.</para> </listitem> </varlistentry> </variablelist> </refsect1> <refsect1><title>Environment</title> <variablelist> <varlistentry> <term><varname>UDEV_LOG=</varname></term> <listitem> <para>Set the logging priority.</para> </listitem> </varlistentry> </variablelist> </refsect1> <refsect1><title>Kernel command line</title> <variablelist> <varlistentry> <term><varname>udev.log-priority=</varname></term> <listitem> <para>Set the logging priority.</para> </listitem> </varlistentry> <varlistentry> <term><varname>udev.children-max=</varname></term> <listitem> <para>Limit the number of parallel executed events.</para> </listitem> </varlistentry> <varlistentry> <term><varname>udev.exec-delay=</varname></term> <listitem> <para>Number of seconds to delay the execution of RUN instructions. This might be useful when debugging system crashes during coldplug cause by loading non-working kernel modules.</para> </listitem> </varlistentry> </variablelist> </refsect1> <refsect1><title>Author</title> <para>Written by Kay Sievers <email>kay.sievers@vrfy.org</email>.</para> </refsect1> <refsect1> <title>See Also</title> <para><citerefentry> <refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum> </citerefentry>, <citerefentry> <refentrytitle>udevadm</refentrytitle><manvolnum>8</manvolnum> </citerefentry></para> </refsect1> </refentry>