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1 | <?xml version='1.0'?> <!--*-nxml-*--> |
2 | <?xml-stylesheet type="text/xsl" href="http://docbook.sourceforge.net/release/xsl/current/xhtml/docbook.xsl"?> | |
3 | <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" | |
4 | "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> | |
5 | ||
6 | <!-- | |
7 | This file is part of systemd. | |
8 | ||
9 | Copyright 2010 Lennart Poettering | |
10 | ||
11 | systemd is free software; you can redistribute it and/or modify it | |
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12 | under the terms of the GNU Lesser General Public License as published by |
13 | the Free Software Foundation; either version 2.1 of the License, or | |
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14 | (at your option) any later version. |
15 | ||
16 | systemd is distributed in the hope that it will be useful, but | |
17 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
18 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
5430f7f2 | 19 | Lesser General Public License for more details. |
eec575d8 | 20 | |
5430f7f2 | 21 | You should have received a copy of the GNU Lesser General Public License |
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22 | along with systemd; If not, see <http://www.gnu.org/licenses/>. |
23 | --> | |
24 | ||
25 | <refentry id="systemd.device"> | |
26 | <refentryinfo> | |
27 | <title>systemd.device</title> | |
28 | <productname>systemd</productname> | |
29 | ||
30 | <authorgroup> | |
31 | <author> | |
32 | <contrib>Developer</contrib> | |
33 | <firstname>Lennart</firstname> | |
34 | <surname>Poettering</surname> | |
35 | <email>lennart@poettering.net</email> | |
36 | </author> | |
37 | </authorgroup> | |
38 | </refentryinfo> | |
39 | ||
40 | <refmeta> | |
41 | <refentrytitle>systemd.device</refentrytitle> | |
42 | <manvolnum>5</manvolnum> | |
43 | </refmeta> | |
44 | ||
45 | <refnamediv> | |
46 | <refname>systemd.device</refname> | |
34511ca7 | 47 | <refpurpose>Device unit configuration</refpurpose> |
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48 | </refnamediv> |
49 | ||
50 | <refsynopsisdiv> | |
e670b166 | 51 | <para><filename><replaceable>device</replaceable>.device</filename></para> |
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52 | </refsynopsisdiv> |
53 | ||
54 | <refsect1> | |
55 | <title>Description</title> | |
56 | ||
57 | <para>A unit configuration file whose name ends in | |
58 | <filename>.device</filename> encodes information about | |
59 | a device unit as exposed in the | |
60 | sysfs/<citerefentry><refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum></citerefentry> | |
61 | device tree.</para> | |
62 | ||
63 | <para>This unit type has no specific options. See | |
64 | <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry> | |
65 | for the common options of all unit configuration | |
66 | files. The common configuration items are configured | |
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67 | in the generic <literal>[Unit]</literal> and |
68 | <literal>[Install]</literal> sections. A separate | |
69 | <literal>[Device]</literal> section does not exist, | |
70 | since no device-specific options may be | |
71 | configured.</para> | |
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72 | |
73 | <para>systemd will automatically create dynamic device | |
74 | units for all kernel devices that are marked with the | |
75 | "systemd" udev tag (by default all block and network | |
76 | devices, and a few others). This may be used to define | |
77 | dependencies between devices and other | |
78 | units.</para> | |
79 | ||
80 | <para>Device units are named after the | |
81 | <filename>/sys</filename> and | |
82 | <filename>/dev</filename> paths they control. Example: | |
83 | the device <filename>/dev/sda5</filename> is exposed | |
84 | in systemd as <filename>dev-sda5.device</filename>. For | |
85 | details about the escaping logic used to convert a | |
86 | file system path to a unit name see | |
87 | <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para> | |
88 | ||
89 | </refsect1> | |
90 | ||
91 | <refsect1> | |
92 | <title>The udev Database</title> | |
93 | ||
94 | <para>The settings of device units may either be | |
95 | configured via unit files, or directly from the udev | |
96 | database (which is recommended). The following udev | |
97 | properties are understood by systemd:</para> | |
98 | ||
e1abd3ef | 99 | <variablelist class='udev-directives'> |
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100 | <varlistentry> |
101 | <term><varname>SYSTEMD_WANTS=</varname></term> | |
102 | <listitem><para>Adds dependencies of | |
103 | type <varname>Wants</varname> from | |
104 | this unit to all listed units. This | |
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105 | may be used to activate arbitrary |
106 | units, when a specific device becomes | |
107 | available. Note that this and the | |
108 | other tags are not taken into account | |
109 | unless the device is tagged with the | |
110 | "<literal>systemd</literal>" string in | |
111 | the udev database, because otherwise | |
112 | the device is not exposed as systemd | |
113 | unit.</para></listitem> | |
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114 | </varlistentry> |
115 | ||
116 | <varlistentry> | |
117 | <term><varname>SYSTEMD_ALIAS=</varname></term> | |
118 | <listitem><para>Adds an additional | |
119 | alias name to the device unit. This | |
120 | must be an absolute path that is | |
121 | automatically transformed into a unit | |
122 | name. (See above.)</para></listitem> | |
123 | </varlistentry> | |
124 | ||
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125 | <varlistentry> |
126 | <term><varname>SYSTEMD_READY=</varname></term> | |
127 | <listitem><para>If set to 0 systemd | |
128 | will consider this device unplugged | |
129 | even if it shows up in the udev | |
130 | tree. If this property is unset or set | |
131 | to 1 the device will be considered | |
132 | plugged the moment it shows up in the | |
133 | udev tree. This property has no | |
c5315881 | 134 | influence on the behavior when a |
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135 | device disappears from the udev |
136 | tree. This option is useful to support | |
137 | devices that initially show up in an | |
8f28cbcd | 138 | uninitialized state in the tree, and for |
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139 | which a changed event is generated the |
140 | moment they are fully set | |
141 | up.</para></listitem> | |
142 | </varlistentry> | |
143 | ||
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144 | <varlistentry> |
145 | <term><varname>ID_MODEL_FROM_DATABASE=</varname></term> | |
146 | <term><varname>ID_MODEL=</varname></term> | |
147 | ||
148 | <listitem><para>If set, this property is | |
149 | used as description string for the | |
150 | device unit.</para></listitem> | |
151 | </varlistentry> | |
152 | ||
153 | </variablelist> | |
154 | ||
155 | ||
156 | </refsect1> | |
157 | ||
158 | <refsect1> | |
159 | <title>See Also</title> | |
160 | <para> | |
f3e219a2 | 161 | <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, |
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162 | <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>, |
163 | <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>, | |
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164 | <citerefentry><refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum></citerefentry>, |
165 | <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry> | |
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166 | </para> |
167 | </refsect1> | |
168 | ||
169 | </refentry> |