Re: Eggs. Basket.
At the prices they're going these days (the 4TB WD easystore was only $80 on a Cyber Monday sale), you can get at least two and mirror and rotate them. If one dies, odds are still passing fair you can get a replacement and re-mirror before the other one goes since you only use one of them at a time (meaning they'll have differing wear patterns that reduce the odds of simultaneous failure).