I am experimenting with using Lubuntu in a virtual machine instead of running Xubuntu from my ancient Linux laptop/server. Lubuntu is a bit less demanding on the system, but this basically means that some stuff are not installed by default.
In particular, with Oracle VM VirtualBox, one of the things under the "very nice to have" list is the Oracle VM VirtualBox Guest Additions. However, Lubuntu by default does not have the prerequisites set up.
To setup the pre-requisites, from Cortman (http://cortman.wordpress.com/2013/03/14/lubuntu-12-10-virtual-box-setup), you need to run the following:
sudo apt-get updateI did not need to run the last line, but that is because my Lubuntu build is relatively new. The blog post from Cortman goes into actual steps of setting up Guest Additions, and also how to share folders between the virtual machine and the host computer.
sudo apt-get install build-essential dkms gcc make
sudo apt-get install linux-headers-$(uname -r)