So I have then adding to my iTunes library quite a bit lately, and now my 4 TB drive is about to run out of space. I have a Probox with room for a total of 16tb. How do I best go about expanding my iTunes library at this point? The majority of my iTunes library are my HD movies. I would like to keep the next storage solution to a reasonable cost (ie, not a $600 box plus another $600 in drives), and keep the storage as a DAS to my late 2012 Mac Mini. The Mac mini acts as my itunes and photo server for my house. Right now I have three 4tb Seagate drives in my Probox. Should I buy a fourth, and try to do a RAID 0 on the first two drives, then back them up on the next two drives? Any input is greatly appreciated.