I do projects like this all of the time using an archival file system from a company called FileTek. FileTek is a software product that presents a tape library as a NAS. You use a small amount of disk as a cache. It then stores the data on tape with redundancy and all kinds of media management. I have several clients using with multiple PBs of capacity. If you contact the company ask for a guy named Diamond and tell him that Jacob sent you. www.filetek.com