chiark / gitweb /
man: fix references to systemctl man page which is now in section 1
[elogind.git] / man / systemd.device.xml
index 96ebe890953fd3c499ab4b8120c2c86089de4496..557f15f906d79615e698ad521c1c2274406da719 100644 (file)
                 since no device-specific options may be
                 configured.</para>
 
                 since no device-specific options may be
                 configured.</para>
 
-                <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>systemd will dynamically create 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. To tag a
+                udev device, use <literal>TAG+="systemd"</literal> in
+                the udev rules file, see
+                <citerefentry><refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum></citerefentry>
+                for details.</para>
 
                 <para>Device units are named after the
                 <filename>/sys</filename> and
 
                 <para>Device units are named after the
                 <filename>/sys</filename> and
 
                 <para>The settings of device units may either be
                 configured via unit files, or directly from the udev
 
                 <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
+                database (which is recommended). The following udev device
                 properties are understood by systemd:</para>
 
                 <variablelist class='udev-directives'>
                         <varlistentry>
                                 <term><varname>SYSTEMD_WANTS=</varname></term>
                 properties are understood by systemd:</para>
 
                 <variablelist class='udev-directives'>
                         <varlistentry>
                                 <term><varname>SYSTEMD_WANTS=</varname></term>
+                                <term><varname>SYSTEMD_USER_WANTS=</varname></term>
                                 <listitem><para>Adds dependencies of
                                 <listitem><para>Adds dependencies of
-                                type <varname>Wants</varname> from
-                                this unit to all listed units. This
-                                may be used to activate arbitrary
-                                units, when a specific device becomes
-                                available. Note that this and the
+                                type <varname>Wants</varname> from the
+                                device unit to all listed units. The
+                                first form is used by the system
+                                systemd instance, the second by user
+                                systemd instances. Those settings may
+                                be used to activate arbitrary units
+                                when a specific device becomes
+                                available.</para>
+
+                                <para>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
                                 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>
+                                the device is not exposed as a systemd
+                                unit (see above).</para>
+
+                                <para>Note that systemd will only act
+                                on <varname>Wants</varname>
+                                dependencies when a device first
+                                becomes active. It will not act on
+                                them if they are added to devices that
+                                are already active. Use
+                                <varname>SYSTEMD_READY=</varname> (see
+                                below) to influence on which udev
+                                event to trigger the dependencies.
+                                </para></listitem>
                         </varlistentry>
 
                         <varlistentry>
                         </varlistentry>
 
                         <varlistentry>
                                 even if it shows up in the udev
                                 tree. If this property is unset or set
                                 to 1, the device will be considered
                                 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
+                                plugged if it is visible in the
                                 udev tree. This property has no
                                 influence on the behavior when a
                                 device disappears from the udev
                                 udev tree. This property has no
                                 influence on the behavior when a
                                 device disappears from the udev
-                                tree. This option is useful to support
+                                tree.</para>
+
+                                <para>This option is useful to support
                                 devices that initially show up in an
                                 devices that initially show up in an
-                                uninitialized state in the tree, and for
-                                which a changed event is generated the
-                                moment they are fully set
-                                up.</para></listitem>
+                                uninitialized state in the tree, and
+                                for which a <literal>changed</literal>
+                                event is generated the moment they are
+                                fully set up. Note that
+                                <varname>SYSTEMD_WANTS=</varname> (see
+                                above) is not acted on as long as
+                                <varname>SYSTEMD_READY=0</varname> is
+                                set for a device.</para></listitem>
                         </varlistentry>
 
                         <varlistentry>
                         </varlistentry>
 
                         <varlistentry>
                   <title>See Also</title>
                   <para>
                           <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
                   <title>See Also</title>
                   <para>
                           <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
-                          <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+                          <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
                           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                           <citerefentry><refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
                           <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>
                           <citerefentry><refentrytitle>systemd.unit</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                           <citerefentry><refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
                           <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>