I've been wanting to do a raid 1 setup in my home with a pair of sata drives. Someone told me that if the controller fails, you can't just get a new controller because you'll have to reformat the drives.

Or is that true only in some implementations? I was originally just looking at an onboard raid controller, or an entry level nas drvice like the intel SS4200-E, but If the hardware (controller) ever fails, will I be out of luck accessing the data if I can't get the exact same hardware to replace it?