It depends on the RAID controller card, hard drives and system you are planning to use. However, the total of the entire array does not have to be 2.19TB. That depends on the setup for the RAID. Most RAID controller cards should support up to 2TB per drive. Anything above is dependent on the system setup of your OS, RAID controller card, etc. For example, the OS's that currently generally show to support over 2TB as boot drives are: Windows Vista 64bit, Windows 7 64-bit and Mac OSX 10.5-10.6. As a secondary drive, most operating systems should be supported.