[Solved] Raid 0 Question

When you create a RAID 0 drive, it looks like one giant disk to the operating system. You can partition that giant disk any way you want, the partitioning has nothing to do with the size of the physical drives (other than that the total space available for partitions is of course the space of both drives put together).

Note that with unequal-sized drives of 300 and 500GB you'll probably only get a total of 600GB of space with the other 200GB on the larger drive unused.