I have a 56 TB local Unraid NAS that is parity protected against single drive failure, and while I think a single drive failing and being parity recovered covers data loss 95% of the time, I’m always concerned about two drives failing or a site-/system-wide disaster that takes out the whole NAS.
For other larger local hosters who are smarter and more prepared, what do you do? Do you sync it off site? How do you deal with cost and bandwidth needs if so? What other backup strategies do you use?
(Sorry if this standard scenario has been discussed - searching didn’t turn up anything.)


I have doubles of the data. Some of 'em. That way I know I have a pristine one in backup. Then I can use it, it gets corrupted, I don’t care.
Actually, I have triples of the W2s. I have triples, right? If I don’t, the other stuff’s not true.
See, the W2s the one I have triples of. Oh, no, actually, I also have triples of the kids photos, too. But just those two. And your dad and I are the same age, and I’m rich and I have triples of the W2s and the kids photos.
Triples makes it safe.
Triples is best.
https://www.youtube.com/watch?v=8Inf1Yz_fgk
Bob Odenkirk has never steered us wrong, thanks. I downloaded three copies of this from YouTube in case I forget.