Answer
You'll have 1TB ... With RAID 10, you'll have 2 sets of mirrored drives ... each mirrored set takes two 500GB drives to store 500GB of data, and your data will be striped across the two sets for a total of 1TB usable storage.
Answer
You'll have 1TB ... With RAID 10, you'll have 2 sets of mirrored drives ... each mirrored set takes two 500GB drives to store 500GB of data, and your data will be striped across the two sets for a total of 1TB usable storage.