Didier:
...
>     Seems there is a myth about user-space hotplugger
> (udev/eudev/vdev/mdev) being necessary to have a dynamic /dev. Dynamic
> /dev has been managed by the kernel from many years. The hotpluggers do
> other things, like managing the symlinks in /dev/disk/by-* and they are
> usefull for that. But, even if you remove the hotplugger, if the kernel
> has the DEVTMPFS feature enabled (which is likely), it will create and
> delete the device files.

The kernel devtmpfs makes dev files come and go, yes, but they
will have some default user, group and permission setting, so
*dev daemons handle that part.

And, if DEVTMPFS isn't used then udev will not start, don't know
about eudev.
vdev and mdev will probably run fine without devtmpfs.

Regards,
/Karl Hammar