virtualbox.org

Is it possible to install VM on the SDXC Card of a Macbook Air 2014 (i5, Mavericks, + 4GB Ram) and running Ubuntu from it. If so, how much Ram and Card space would one need to allocate to the VM in order to run it acceptable? I would appreciate feedback?

It's possible to locate a VM on any drive which the host can access, including memory card drives. The VM would run, but it would probably be very very slow. VirtualBox would still have to be installed on the host.