Basically I have reasonably fast home network of 100mb up and 5mb down .. I have my Mac Mini wired to the router to take advantage of this. It acts as a media server and streams movie content around my house to various clients. However I have run out of disk space. Do I a) Buy a 2x2TB NAS and use 2 of it as storage and 2 of it as back up b) Buy a 2x2TB drive (as I dont need it to be wireless) and use RAID1 to mirror the contents of drives so 1 is storage and 1 is backup Im rather confused and dont know how RAID works if Im entirely honest.