huschi.net

SYSTEMD.DEVICE(5)               systemd.device               SYSTEMD.DEVICE(5)

NAME
       systemd.device - Device unit configuration
SYNOPSIS
       device.device
DESCRIPTION
       A unit configuration file whose name ends in ".device" encodes
       information about a device unit as exposed in the sysfs/udev(7) device
       tree.
       This unit type has no specific options. See systemd.unit(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.
       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
       "TAG+="systemd"" in the udev rules file, see udev(7) for details.
       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 systemd.unit(5).
THE UDEV DATABASE
       The settings of device units may either be configured via unit files,
       or directly from the udev database (which is recommended). The
       following udev device properties are understood by systemd:
       SYSTEMD_WANTS=
           Adds dependencies of type Wants from the device unit to all listed
           units. This settings 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 "systemd" string in the udev
           database, because otherwise the device is not exposed as a systemd
           unit (see above).
           Note that systemd will only act on Wants dependencies when a device
           first becomes active. It will not act on them if they are added to
           devices that are already active. Use SYSTEMD_READY= (see below) to
           influence on which udev event to trigger the dependencies.
       SYSTEMD_ALIAS=
           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.)
       SYSTEMD_READY=
           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. This property has no influence on the behavior when a device
           disappears from the udev tree.
           This option is useful to support 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
           SYSTEMD_WANTS= (see above) is not acted on as long as
           SYSTEMD_READY=0 is set for a device.
       ID_MODEL_FROM_DATABASE=, ID_MODEL=
           If set, this property is used as description string for the device
           unit.
SEE ALSO
       systemd(1), systemctl(1), systemd.unit(5), udev(7),
       systemd.directives(7)

systemd 219                                                  SYSTEMD.DEVICE(5)