I've made a Script for making the whole process of Mounting Virtualbox VDI disks in Ubuntu less of a pain. This script should work in any Debian OS but I can't garuntee it as I have yet to test it on anything but Ubuntu.
The Script has a lot of bells and whistles so let me know if you find a Bug or have other suggestions.
-Optional Install to /usr/bin to allow easy command use(ie: just type vdimount to use it)(If you say no but wish to install it later simply use th "rs" option in the script)
-AutoCheck if needed Dependencies are Installed
-Give Option to Install and Setup needed Dependencies if not Installed
-Once Selected, Partition Table for VDI is Displayed
-Choose which Partition in VDI to Mount
-Check if a VDI is mounted and give Details on Mount
Features I'm Working On:
-Multiple Partition Mounting
-Multiple VDI Mounting
-More Informative Display
-More Informative Error Checks and Displays
-... Whatever else I think of(or if you have an Idea post below)