Originally Posted by GothicGothicness 
5tb ? I think your solution will be to think what you really need, instead of thinking about a good backup solution. I can hardly imagine someone needing 5tb of personal very important data, unless they are crazy about video or photo editing.
I tend to store as much as possible digitally. The bulk of my harddrive content consists of collections built up over time that acts like a library that can be searched and browsed. For example, I have a western philosophers ebook collection that I occasionally go into if I hear about a certain philosopher that I need to check up. I also have a massive collection of documentaries on history that I tend to watch when I have nothing better to do.
Most of these collections can be downloaded again via the web so it wouldn't be that much of a loss if the harddrives died, some of the collections can remain untouched for a long time until some sudden idea makes me go back to them.
Then there's of course personal data such as schoolwork, projects etc and they cover much less space.