I've settled on a 256GB SSD as internal storage for the 4K 21.5" iMac I'm looking to buy. I was considering a 2TB fusion drive but I figured that I only have a handful of files that I frequently need to access, and the 256GB is more than sufficient for that. Why would I want a constantly spinning hard drive generating heat and noise for files that I rarely have to access? The downside of this solution is of course that I'll need two external copies of my data instead of one. What would you consider the most elegant solution/product(s) for having two external copies of my data? 1TB of storage per copy of the data is probably sufficient. I cannot think of anything other than two 2.5" external hard drives. Is there a better option? I'd love to hear it!