I'm not an expert but I'd mix a RAID with a backup. And the RAID could be a 10 or a 01, but better read about all the types and choose the one that better suits your need.
"The possibility"? Really? Either you have it or not. And until you have it, you don't. Full stop. Or else we go to the "there are WMD in Iraq (trust me, bro)" again.
At? Sometimes I don't remember it on the fly