I tried creating a new Storage Pool with 4 new empty drives attached in a Medium VM.
Failed with "invalid parameter" error. See screenshot below.
Tried deleting drives, attached 2 new ones, same error.
Reboots did not solve it.
The closes I could find is this article, goes nowhere for me http://msdn.microsoft.com/en-us/library/windows/desktop/Hh830483(v=vs.85).aspx