How do you effectively backup your high capacity (20+ TB) local NAS?

https://lemmy.world/post/43604046

How do you effectively backup your high capacity (20+ TB) local NAS? - Lemmy.World

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 don’t. Of my 120tb, I only care about the 4tb of personal data and I push that to a cloud backup. The rest can just be downloaded again.
Do you have logs or software that keeps track of what you need to redownload? A big stress for me with that method is remembering or keeping track of what is lost when I and software can’t even see the filesystem anymore.

If you can’t remember what you lost, did you really need it to begin with?

Unless it’s personal memories of course.

For me, I have a bad memory. I might remember a childhood movie (a nickname I give to special Linux ISOs) that I hadn’t even thought of for 10 years and track down a copy, sometimes excavating obscure sources, and that may be hours of one-time inspiration and work repeated many times over. Having a complete list is a good helper, but a full backup of course is best.