My office is supposed to retain 60 days of video. The 1280/720 ip non IR cameras are mostly set for 15 FPS with two set at 30 FPS. Motion detection on. I had to point out to the security guy that his settings were causing the data to be overwritten every 5 days. Constant bit rate is the configuration. If all but the two cashier cameras are set to 7 FPS it still seems like the 4 TB is way too small for this many cameras. No motion to record from 5:30 pm to about 6:30 am as employees start trickling in. 20 of the cameras are pointed at doors. Any advice on FPS, variable bit rate or hard drive size would be appreciated.