Ok I have a question about raid and internal mac pro hardrives. I have 1 stock mac pro hard drive that has the OS and everything on it. Now I want to purchase three 1.5 tb drives to put in the three empty drive bays of the mac pro. How would I keep my stock hard drive separate from the other three 1.5 hard drives in the system? I want to have the three 1.5 terabyte hard drives act as one big one so I see one partition as 4.5 tb and still see my system drive separate as 650 gb or whatever it was. Can this be done without loosing data or no?