Can't get the shared clipboard to work on Ubuntu 14.04

Solution 1:

The VirtualBox guest additions provide clipboard integration between the host and a X11 GUI running in the guest. They don't provide clipboard integration with a Linux console guest (there is a feature request for this, but it's understandably very low priority, because very few people use that feature).

If you want a comfortable interface inside the guest, install a GUI, for a negligible added cost in disk space. Use a lighter GUI than Gnome/Unity if you want to save RAM.

If you want a comfortable command line interface to the guest, use SSH in a terminal emulator of your choice running in the host. Use the console inside the guest only when you've screwed up the firewall.