[Nbd] Boot a virtualbox guest using a remote dvd drive accessed by nbd

[Peter Nield <nieldp@...17...>]

I apologise in advance if this appears a stupid/obvious question.

I am trying to use a remote dvd drive to start a dvd distro on a pc with 
no dvd drive (hence I'm trying nbd).

Virtualbox has 2 methods for starting a guest by cd/dvd.

  1. Mount a dvd on the host machine
  2. Mount an iso image from harddisk

The latter method works for me if I mount the nbd device and point VB at 
the iso image on the dvd volume.
The former gives a 0003 error and says it cannot read the dvd.

I read in a former post (related to dvd/rw drives) that nbd did not 
support ioctl()'s other than read/write.
Could this be the reason for the boot failure?
I'm not a low level programmer and hence this question.
Suggestions and pointers welcome.