UDEVD(8)                 Linux Administrator's Manual                 UDEVD(8)

       udevd, udevdsend - udev event serializer daemon and udev event sender

       udevsend hotplug-subsystem

       The environment must provide the following variables:

       ACTION add or remove signifies the connection or disconnection of a

              The sysfs devpath of the device without the mountpoint but a
              leading slash.

       SEQNUM The sequence number of the event provided by the kernel.  If
              unset, the event bypasses the queue and will be executed

       udevd allows the serialization of hotplug(8) events. The events
       generated by the kernel may arrive in random order in userspace, that
       makes it neccessary to reorder them.
       udevd takes care of the kernel supplied sequence number and arranges
       the events for execution in the correct order. Missing sequences delay
       the execution of the following events until a timeout is reached.
       For each event a udev(8) instance is executed in the background. All
       further events for the same device are delayed until the execution is
       finished. This way there will never be more than one instance running
       for a single device at the same time.
       udevd receives the events from udevsend which is called by hotplug(8).
       If udevd isn't already running, udevsend will start it.

       udev(8), udevinfo(8), hotplug(8)

       udevd was developed primarily by Kay Sievers <kay.sievers@vrfy.org>,
       with much help from others.

                                 February 2004                        UDEVD(8)