DVR info

I recently upgraded my services and added basic tv, my XG2v2-p tv box holds about 9hrs of recordings. Question, the box has both a Cat5 and usb ports. Can a remote hard drive be attached as extra storage or can it be connected to my network with access to available storage space? Or are they only for diagnostic use? If a usb drive can be used what system should it be formated in as to be readable by the box, ext2 or some linux structure?