Bug#728486: Current patch for resolving lvm/systemd compatibility

[Laurent Bigonville <bigon@debian.org>]

Hi,

Just came here to add my 2¢ about this in the light of my recent
experience I had with an other package (nut) where devices were not
present when the daemon was starting.

My initial solution was also to depends against udev-settle.service
service. This was ensuring that the devices were present in /dev in
some, but certainly, not all the cases, especially if the device was
slow to initialize.

After some discussion on #udev, it turns out that "udevadm settle" is
merely flushing the queue of already generated events and it, of course,
cannot guarantee in anyway that all the events have been generated by
the kernel.

So IMHO, adding udev-settle.service shouldn't be the long term
solution, it will make things work in more case, but not all. And the
correct solution is to have something like the generator that will
allow to handle events when they are generated and not at one
synchronization point during boot.

My 2¢

Laurent Bigonville