From Sweetwater Sound’s Service Department:
Advice for users of hard disk-based recording systems: Hard drives are mechanical devices and as such will eventually fail! If you are recording to hard disk, then your drive is like the tape in an analog system – if you don’t have tape, you can’t get any work done. We recommend that if you can’t afford down time, then in addition to regular data backups, you should always have an extra hard drive on hand to get you through emergencies. If your time is valuable (and whose isn’t?), or your clients and deadlines are waiting (and whose aren’t?), then the cost of a spare drive is truly inconsequential (especially at today’s prices)!
Actually, we recommend this policy for all critical gear in your studio or rig. Go to a major concert sometime and check out the sound mix position. You will see one or even two spare power supplies in the rack for the mixer.
The moral of the story? Can’t afford down time? Have a spare…