I was stuck some days back with space problem in my Virtual hard disc, which runs with VirtualBox. It was deactivating & locking the screen within a minute I started it.
It was a quite panic situation. My operating system at that time was Ubuntu Karmic.
Many users said that it solved their problem, but it didn’t work in my part as VirtualBox was not letting me to open my VM so that I can shrink my VDI image.
So I opted for suggestion No. 2 Visit Site
Now I downloaded nullfile.exe & did as said by the site (Suggetion No. 2) EXCEPT defraging as I was unable to do so. The whole process took near about 18 hours & the result was WOW! it compressed it 16GB to 4GB, just 1/4th. It solved my problem for the time being but I’m not sure that is it the right process or not. Comments are welcome.