Yes you can and you can purchase this from the link below and you do not have to buy the full version and you can keep adding more 2TB or higher storage license keys.

http://www.open-e.com/store/

Check to see if you can remove older release from the GUI in Maint. > Software update.

All information is in the release notes with the list and all previous versions with fixes known issues. They in your user portal from where you downloaded the DSS V6 Lite.