I Just purchased a Dell R710 with 2 160gb SATA Drives. Then ordered 4 600gb 6gb SAS drives. I am planning to run ESX4 on this this. For maximum performance is it better to run the VWare OS on the 2 SATA drives mirrored and the 4 SAS drives in Raid 5 or remove the 2 SATA Drives and run the OS and data on the 4 SAS drives in a Raid 5? I am planning to purchase more SAS drives in the future.