systemd.device
systemd
Developer
Lennart
Poettering
lennart@poettering.net
systemd.device
5
systemd.device
systemd device configuration files
systemd.device
Description
A unit configuration file whose name ends in
.device encodes information about
a device unit as exposed in the
sysfs/udev7
device tree.
This unit type has no specific options. See
systemd.unit5
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 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.
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.unit5.
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
properties are understood by systemd:
SYSTEMD_WANTS=
Adds dependencies of
type Wants 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
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 systemd
unit.
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.)
ID_MODEL_FROM_DATABASE=
ID_MODEL=
If set, this property is
used as description string for the
device unit.
See Also
systemd1,
systemctl8,
systemd.unit5,
udev7