RAID 1 is best used for fast recovery, not backup. RAID 1 is designed for getting the OS drive back online within a few seconds after a failure, or in business situations where the data on the storage drive needs to be restored ASAP. For a home user who wants a backup solution, I recommend installing storage drives in non-RAID mode and synchronizing their data a few times per day. This way you don't have to worry about finding an identical make and model drive / motherboard / controller card if something dies. If you are using Linux / UNIX / Mac OS X you can run rsync as a cron job in the background once or twice per day. If you are in Windows, the freeware Syncback program is a very solid solution.