With RAID mirroring (mode 1) you have two drives of equal capacity. They do
exactly what they say ... mirror ... what is on one is also on the other.
When data is sent to the hard drive both of them receive and store the data.
This provides security thru redundancy, because it's unlikely that you would
have two drives go bad at the same time ... and if one *does* go bad, well
you've got the other one there with a complete copy of your data.
Simple enough for ya?
Drumguy