adrahon/vagrant-kvm — pull request #24 by simonjj (2013-07-18 02:02:21+00:00)
Title: switch from raw to qcow2 images to take advantage of dynamic allocation

Raw images are quite big since they get fully allocated all the time. I believe that qcow2 is a better choice for multiple reasons. Please http://en.wikibooks.org/wiki/QEMU/Images#Image_types for more details.