Raid is not a backup solution, it is intended for fault tolerance. as the number of drives is increased the likelihood of drive failure goes up. also when a drive fails you need a drive with the same specs, which may or may not be resonable if some time has passed since the raid was initialized. Lastly if you raid controller goes down you are hosed. other than those issues its great.

I used two backup mobile drives (1 TB each) as alternatives

Ever since I can remember, books have been a hugely important part of my life. There's no doubt that other than food and shelter, reading material is the one material item I couldn't live without. Everything else is extra, but books are essential.

Now, like a dream come true, and despite the fact that I am family man of very modest means, and thanks to (primarily) amazing people on this site, I have literally more than enough to read for the rest of my life.

So how do I protect my library? Obviously I have to backup, but where do I keep my backup? What's the way they will be most safe, and how safe can they be?

As you can tell, I'm not especially IT savvy, so forgive me if these are stupid questions but as fellow book lovers and generous folk, I thought surely someone would be willing to give me a tip or two.

Thanks in advance and thank you all for participating on this site.

Seems like dropbox, one drive or some other free online storage is what you need