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 3 main NASes
78TB (52TB usable) hot storage. ZFS1
160TB (120TB) warm storage ZFS2
48TB (24TB) off site. ZFS mirror
I rsync every day from hot to off site.
And once a month I turn on my warm storage and sync it.
Warm and hot storage is at the same location.
Off site storage is with a family friend who I trust. Data isn’t encrypted aside from in transit. That’s something else I’d like to mess with later.
Core vital data is sprinkled around different continents with about 10TB. I have 2 nodes in 2 countries for vital data. These are with family.
I think I have 5 total servers.
Cost is a lot obviously, but pieced together over several years.
The world will end before my data gets destroyed.
But would your data survive a nearby gamma-ray burst?
Amateurs not keeping at least one backup off-planet SMH
I put a QNAP on the ISS. Expensive, but I sleep soundly.