I have an external that backs up every day (actually every few hours). I also back up on DVDs. I only back up the RAW files or original JPGs. I also back up on a 2nd external every few weeks or month. I do not have this one connected to the computer. I only plug it in when I back up. I keep this on in a safe place (gun locker at work) in a secured area with no moisture. I do not have anything "secret" or patented, just family pics, but I would hate to see them all get lost due to a power surge, disaster ect.

I also live next to a military airfield and am in the flight path so there is always a possibility of aircraft accidents.

Just my .02....

Phil