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-rw-r--r-- | upstream/opensuse-tumbleweed/man5/systemd.device.5 | 138 |
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diff --git a/upstream/opensuse-tumbleweed/man5/systemd.device.5 b/upstream/opensuse-tumbleweed/man5/systemd.device.5 new file mode 100644 index 00000000..0a10fc79 --- /dev/null +++ b/upstream/opensuse-tumbleweed/man5/systemd.device.5 @@ -0,0 +1,138 @@ +'\" t +.TH "SYSTEMD\&.DEVICE" "5" "" "systemd 254" "systemd.device" +.\" ----------------------------------------------------------------- +.\" * Define some portability stuff +.\" ----------------------------------------------------------------- +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.\" http://bugs.debian.org/507673 +.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.ie \n(.g .ds Aq \(aq +.el .ds Aq ' +.\" ----------------------------------------------------------------- +.\" * set default formatting +.\" ----------------------------------------------------------------- +.\" disable hyphenation +.nh +.\" disable justification (adjust text to left margin only) +.ad l +.\" ----------------------------------------------------------------- +.\" * MAIN CONTENT STARTS HERE * +.\" ----------------------------------------------------------------- +.SH "NAME" +systemd.device \- Device unit configuration +.SH "SYNOPSIS" +.PP +\fIdevice\fR\&.device +.SH "DESCRIPTION" +.PP +A unit configuration file whose name ends in +"\&.device" +encodes information about a device unit as exposed in the sysfs/\fBudev\fR(7) +device tree\&. This may be used to define dependencies between devices and other units\&. +.PP +This unit type has no specific options\&. See +\fBsystemd.unit\fR(5) +for the common options of all unit configuration files\&. The common configuration items are configured in the generic [Unit] and [Install] sections\&. A separate [Device] section does not exist, since no device\-specific options may be configured\&. +.PP +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)\&. Note that +\fIif \fR\fIsystemd\-udevd\&.service\fR\fI is not running, no device units will be available (for example in a typical container)\fR\&. +.PP +Device units are named after the +/sys/ +and +/dev/ +paths they control\&. Example: the device +/dev/sda5 +is exposed in systemd as +dev\-sda5\&.device\&. For details about the escaping logic used to convert a file system path to a unit name see +\fBsystemd.unit\fR(5)\&. +.PP +To tag a udev device, use +"TAG+="systemd"" +in the udev rules file, see +\fBudev\fR(7) +for details\&. +.PP +Device units will be reloaded by systemd whenever the corresponding device generates a +"changed" +event\&. Other units can use +\fIReloadPropagatedFrom=\fR +to react to that event\&. +.SH "AUTOMATIC DEPENDENCIES" +.SS "Implicit Dependencies" +.PP +Many unit types automatically acquire dependencies on device units of devices they require\&. For example, +\&.socket +unit acquire dependencies on the device units of the network interface specified in +\fIBindToDevice=\fR\&. Similar, swap and mount units acquire dependencies on the units encapsulating their backing block devices\&. +.SS "Default Dependencies" +.PP +There are no default dependencies for device units\&. +.SH "THE UDEV DATABASE" +.PP +Unit settings of device units may either be configured via unit files, or directly from the udev database\&. The following udev device properties are understood by the service manager: +.PP +\fISYSTEMD_WANTS=\fR, \fISYSTEMD_USER_WANTS=\fR +.RS 4 +Adds dependencies of type +\fIWants=\fR +from the device unit to the specified units\&. +\fISYSTEMD_WANTS=\fR +is read by the system service manager, +\fISYSTEMD_USER_WANTS=\fR +by user service manager instances\&. These properties may be used to activate arbitrary units when a specific device becomes available\&. +.sp +Note that this and the other udev device properties are not taken into account unless the device is tagged with the +"systemd" +tag in the udev database, because otherwise the device is not exposed as a systemd unit (see above)\&. +.sp +Note that systemd will only act on +\fIWants=\fR +dependencies when a device first becomes active\&. It will not act on them if they are added to devices that are already active\&. Use +\fISYSTEMD_READY=\fR +(see below) to configure when a udev device shall be considered active, and thus when to trigger the dependencies\&. +.sp +The specified property value should be a space\-separated list of valid unit names\&. If a unit template name is specified (that is, a unit name containing an +"@" +character indicating a unit name to use for multiple instantiation, but with an empty instance name following the +"@"), it will be automatically instantiated by the device\*(Aqs +"sysfs" +path (that is: the path is escaped and inserted as instance name into the template unit name)\&. This is useful in order to instantiate a specific template unit once for each device that appears and matches specific properties\&. +.RE +.PP +\fISYSTEMD_ALIAS=\fR +.RS 4 +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\&.) +.RE +.PP +\fISYSTEMD_READY=\fR +.RS 4 +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 if it is visible in the udev tree\&. +.sp +This option is useful for 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\&. Note that +\fISYSTEMD_WANTS=\fR +(see above) is not acted on as long as +\fISYSTEMD_READY=0\fR +is set for a device\&. +.RE +.PP +\fIID_MODEL_FROM_DATABASE=\fR, \fIID_MODEL=\fR +.RS 4 +If set, this property is used as description string for the device unit\&. +.RE +.SH "OPTIONS" +.PP +Device unit files may include [Unit] and [Install] sections, which are described in +\fBsystemd.unit\fR(5)\&. No options specific to this file type are supported\&. +.SH "SEE ALSO" +.PP +\fBsystemd\fR(1), +\fBsystemctl\fR(1), +\fBsystemd.unit\fR(5), +\fBudev\fR(7), +\fBsystemd.directives\fR(7) |