When a salesman for Verizon FiOS stopped by on June 9 I asked about the FiOS Motorola DVR HD recording capacity which is about 18 hours using a small internal hard drive and when an external hard drive could be added. He told me they were working on the software and it would be available in one month so I subscribed. But here it is near the middle of September and the DVR still will not support an external hard drive to increase capacity. Tech support yesterday told me it was a copy write issue but Time Warner, Comcast, TiVO, and other companies have solved that problem and support an external drive to increase recording time.
My advice is either get your cable service from other than Verizon or do NOT buy their DVR and get a TiVO instead. I would switch but signed a two year contract based on the salesman's assurance that an external drive would be supported by August.
Bob