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xml version='1.0'?>
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DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" <
productname>systemd</
productname>
<
contrib>Developer</
contrib>
<
firstname>Kay</
firstname>
<
surname>Sievers</
surname>
<
email>kay@vrfy.org</
email>
<
refname>systemd-udevd</
refname>
<
refpurpose>Device event managing daemon</
refpurpose>
<
command>&rootlibexecdir;/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>
<
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>
<
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
<
refsect1><
title>Options</
title>
<
term><
option>--daemon</
option></
term>
<
para>Detach and run in the background.</
para>
<
term><
option>--debug</
option></
term>
<
para>Print debug messages to standard error.</
para>
<
term><
option>--children-max=</
option></
term>
<
para>Limit the number of events executed in parallel.</
para>
<
term><
option>--exec-delay=</
option></
term>
<
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
<
term><
option>--event-timeout=</
option></
term>
<
para>Set the number of seconds to wait for events to finish. After
this time the event will be terminated. The default is 30 seconds.</
para>
<
term><
option>--resolve-names=</
option></
term>
<
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>
<
term><
option>--help</
option></
term>
<
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>
<
para>Set the log level.</
para>
<
para>Limit the number of events executed in parallel.</
para>
<
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>
<
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>
<
para>Network interfaces are renamed to give them predictable names
when possible. It is enabled by default; specifying 0 disables it.</
para>
<!-- when adding entries here, consider also adding them <
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>