A:Answer Depends on drive size, number of active channels, settings, sensitivity, capture's, image quality, alarms, events, pictures, videos, and SAVED events. The 2TB/8 camera unit might get 2.5 to 3 days at max capture setting. I do not see any information on adding an internal drive. Easy enough to plug an external drive in and save the events if needed. Best to have events stored on cloud so you can go back at any time.