The Gigabyte X58-EXTREME board has a 6-port Intel controller. My array is 4 x 1.5TB drives in a redundant performance configuration (0+1).

Can I create a R.A.I.D. 0, copy the data to it (from a drive broken away from the mirror), and then upgrade the '0' to a R.A.I.D. 0+1?

The resulting storage yield is larger than 2TB, which creates the need for two arrays or a G.P.T. partition. To avoid G.P.T., I would prefer to recreate two (0+1) arrays, each sized ~1.5TB.

The problem is that the storage is full. I can break the mirror for a temporary backup solution, if it is possible to upgrade an performance array to performance and mirroring.