In the article on RAID levels for small businesses it was stated about RAID 1:
“This level offers data recoverability, but it comes at the cost of performance, since every disk action occurs multiple times.”
This isn’t completely accurate. Writes are performed twice, but reads are only performed once. Also, reads can be made from whichever disk is not busy. In other words if a write – whether the first write or redundant write is being made to the first disk, a read can be made from the other disk.
