I always try to tell people this, buy two, set yourself up a raid backup. Everything should be replicated on a second external drive. HD's have a life expectancy like anything else. I have seen people lose a life's work over a $150.00. The Second hard drive is only ever fired up to back up the back up, maybe once a week or so, and I keep a copy of all my computer and photos on a third that is in my saftey deposit box. It may seem extreme but I work from home and my life's work is on my computer and what I need to make an income. I use 3 external HD's, the one in the Safety Deposit Box comes home for an hour or two once a month, backs up my back ups and put in storage. A house fire, flood or any other catastrophe may occur, are you willing to lose everything? just a word of Advice. You may think it won't happen to you, but for the cost is it not worth thinking about, you put all your photos on a HD, turns out you get a defective one, a month later it just crashes taking all your files with it, you may be able to recover some but that can be a very costly procedure. I prefer mine on separate cases, I know what the dual are supposed to do, but I have seen them fail horribly. Again just my opinion.