This problem occurs with regular Ubuntu 16.04 too. The Ubuntu logo hangs for some time, then I hear a beep sound from the tower, then the boot process continues. This happens every time I boot.
The problem doesn’t occur with the open-source drivers (the xorg drivers).
Looks like the hang is triggered by nvidia-smi, so the question is what starts that and why. Maybe start by checking your systemd units and udev rules.
as for udev rules, I checked the directory “/usr/lib/udev/” but it doesn’t exist, and the directory “/etc/udev/rules.d/” but it doesn’t seem to have anything that’s Nvidia related
I’ve taken a look at the driver package, nvidia-smi is started by the udev rule in
/lib/udev/rules.d/71-nvidia.rules
to create the /dev nodes.
IIRC, ubuntu doesn’t ship the suid nvidia-modprobe which would be used otherwise. Maybe check if commenting out the line udev rules file will still create the nodes.
From my experience, using nvidia-smi for that purpose will in rare cases lead to that hang you’re having, but don’t ask me why.