hungfsu

I bought a rack mount system used with Eyemax DV 9120 and installed it in my business with 16 cameras. The system seems to be working fine, but it is only keeping the last four hours of video. I've been trying to figure out how to extend the length of video, but can't seem to find where those settings are. I checked my hard drive and it is not full. Can someone help? Also, how do I set it up so that I can view the video via the web? Thanks in advance for your help.