virtualbox.org

Hello, my teacher asks us to download a Debian version from another university link, in a .vmdk type.
My problem now, is that this file-size was 8GB, now, using this OS with virtual box, the space is over. Is there a method in order to increase the size of .vmdk, without reinstall the OS?
I attach the virtual box mainpage summary.

Thank you.

See How to resize a Virtual Drive and especially step #2

Be sure to read the second topic in that link first then go to the first.