2010-07-02 05:28:33 +04:00
<?xml version='1.0'?> <!-- * - nxml - * -->
<?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">
<!--
This file is part of systemd.
Copyright 2010 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
2012-04-12 02:20:58 +04:00
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
2010-07-02 05:28:33 +04:00
(at your option) any later version.
systemd is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
2012-04-12 02:20:58 +04:00
Lesser General Public License for more details.
2010-07-02 05:28:33 +04:00
2012-04-12 02:20:58 +04:00
You should have received a copy of the GNU Lesser General Public License
2010-07-02 05:28:33 +04:00
along with systemd; If not, see <http: / / w w w . g n u . o r g / l i c e n s e s /> .
-->
<refentry id= "systemd.device" >
<refentryinfo >
<title > systemd.device</title>
<productname > systemd</productname>
<authorgroup >
<author >
<contrib > Developer</contrib>
<firstname > Lennart</firstname>
<surname > Poettering</surname>
<email > lennart@poettering.net</email>
</author>
</authorgroup>
</refentryinfo>
<refmeta >
<refentrytitle > systemd.device</refentrytitle>
<manvolnum > 5</manvolnum>
</refmeta>
<refnamediv >
<refname > systemd.device</refname>
<refpurpose > systemd device configuration files</refpurpose>
</refnamediv>
<refsynopsisdiv >
<para > <filename > systemd.device</filename> </para>
</refsynopsisdiv>
<refsect1 >
<title > Description</title>
<para > A unit configuration file whose name ends in
<filename > .device</filename> encodes information about
a device unit as exposed in the
sysfs/<citerefentry > <refentrytitle > udev</refentrytitle> <manvolnum > 7</manvolnum> </citerefentry>
device tree.</para>
<para > This unit type has no specific options. See
<citerefentry > <refentrytitle > systemd.unit</refentrytitle> <manvolnum > 5</manvolnum> </citerefentry>
for the common options of all unit configuration
files. The common configuration items are configured
2010-07-06 05:20:49 +04:00
in the generic <literal > [Unit]</literal> and
<literal > [Install]</literal> sections. A separate
<literal > [Device]</literal> section does not exist,
since no device-specific options may be
configured.</para>
2010-07-02 05:28:33 +04:00
<para > systemd will automatically create dynamic device
units for all kernel devices that are marked with the
"systemd" udev tag (by default all block and network
devices, and a few others). This may be used to define
dependencies between devices and other
units.</para>
<para > Device units are named after the
<filename > /sys</filename> and
<filename > /dev</filename> paths they control. Example:
the device <filename > /dev/sda5</filename> is exposed
in systemd as <filename > dev-sda5.device</filename> . For
details about the escaping logic used to convert a
file system path to a unit name see
<citerefentry > <refentrytitle > systemd.unit</refentrytitle> <manvolnum > 5</manvolnum> </citerefentry> .</para>
</refsect1>
<refsect1 >
<title > The udev Database</title>
<para > The settings of device units may either be
configured via unit files, or directly from the udev
database (which is recommended). The following udev
properties are understood by systemd:</para>
<variablelist >
<varlistentry >
<term > <varname > SYSTEMD_WANTS=</varname> </term>
<listitem > <para > Adds dependencies of
type <varname > Wants</varname> from
this unit to all listed units. This
2010-07-06 05:20:49 +04:00
may be used to activate arbitrary
units, when a specific device becomes
available. Note that this and the
other tags are not taken into account
unless the device is tagged with the
"<literal > systemd</literal> " string in
the udev database, because otherwise
the device is not exposed as systemd
unit.</para> </listitem>
2010-07-02 05:28:33 +04:00
</varlistentry>
<varlistentry >
<term > <varname > SYSTEMD_ALIAS=</varname> </term>
<listitem > <para > Adds an additional
alias name to the device unit. This
must be an absolute path that is
automatically transformed into a unit
name. (See above.)</para> </listitem>
</varlistentry>
2011-02-09 17:02:03 +03:00
<varlistentry >
<term > <varname > SYSTEMD_READY=</varname> </term>
<listitem > <para > If set to 0 systemd
will consider this device unplugged
even if it shows up in the udev
tree. If this property is unset or set
to 1 the device will be considered
plugged the moment it shows up in the
udev tree. This property has no
influence on the behaviour when a
device disappears from the udev
tree. This option is useful to support
devices that initially show up in an
2011-04-23 23:55:24 +04:00
uninitialized state in the tree, and for
2011-02-09 17:02:03 +03:00
which a changed event is generated the
moment they are fully set
up.</para> </listitem>
</varlistentry>
2010-07-02 05:28:33 +04:00
<varlistentry >
<term > <varname > ID_MODEL_FROM_DATABASE=</varname> </term>
<term > <varname > ID_MODEL=</varname> </term>
<listitem > <para > If set, this property is
used as description string for the
device unit.</para> </listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1 >
<title > See Also</title>
<para >
2010-07-07 03:38:56 +04:00
<citerefentry > <refentrytitle > systemd</refentrytitle> <manvolnum > 1</manvolnum> </citerefentry> ,
2010-07-02 05:28:33 +04:00
<citerefentry > <refentrytitle > systemctl</refentrytitle> <manvolnum > 8</manvolnum> </citerefentry> ,
<citerefentry > <refentrytitle > systemd.unit</refentrytitle> <manvolnum > 5</manvolnum> </citerefentry> ,
<citerefentry > <refentrytitle > udev</refentrytitle> <manvolnum > 7</manvolnum> </citerefentry>
</para>
</refsect1>
</refentry>
