This is just a hint für using Virtualbox 4.x and Ubuntu 10.4 with Virtualbox guest additions.
For Ubuntu 10.4 it is required to load the guest additions different and not from the
delivered Virtualbox iso with the following commands.
sudo apt-get update sudo apt-get install build-essential linux-headers-$(uname -r) sudo apt-get install virtualbox-ose-guest-x11
Otherwise it will not be possible to use the guest additions and the kernel will not be rebuild correctly.
Work with snapshots after each installation step to have the possibility to roll back.
The hints below stay valid.
The Ubuntu 8.04&EMC2 Live CD available for download on the front page of linuxcnc.org will install inside a virtualbox vm.
Use the iso image inside virtualbox for the as the image for the cd drive during installation.
8 GB for the virtual hard disk seems sufficent. (hard disk is 43% used after installation with additional packages for compiling from git sources ).
You might need to uncomment this line from your ini file (thanks to Alex Joni):
# Name of NML file to use, default is emc.nml<br> #NML_FILE = emc.nml<br>
Maximilian_H, August 2010