<cmdsynopsis>
<command>udevd</command>
<arg><option>--daemon</option></arg>
- <arg><option>--children-max</option></arg>
<arg><option>--debug</option></arg>
- <arg><option>--version</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 and passes the incoming events to
- udev. It ensures the correct event order and takes care, that events for child
- devices are delayed until the parent event has finished the device handling.
- The behavior of the running daemon can be changed with
+ <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>/usr/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>
</listitem>
</varlistentry>
<varlistentry>
- <term><option>--children-max</option></term>
+ <term><option>--debug</option></term>
<listitem>
- <para>Limit the number of parallel executed events.
- </para>
+ <para>Print debug messages to stderr.</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><option>--debug</option></term>
+ <term><option>--children-max=</option></term>
<listitem>
- <para>Print debug messages to stderr.</para>
+ <para>Limit the number of parallel executed events.</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><option>--resolve-names</option></term>
+ <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
<refsect1><title>Environment</title>
<variablelist>
<varlistentry>
- <term><option>UDEV_LOG</option></term>
+ <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>Overrides the syslog priority specified in the config file.</para>
+ <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>
<title>See Also</title>
<para><citerefentry>
<refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum>
- </citerefentry>,
- <citerefentry>
+ </citerefentry>, <citerefentry>
<refentrytitle>udevadm</refentrytitle><manvolnum>8</manvolnum>
</citerefentry></para>
</refsect1>