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.)
For me, I only back up data I can’t replace, which is a small subset of the capacity of my NAS. Personal data like photos, password manager databases, personal documents, etc. get locally encrypted, then synced to a cloud storage provider. I have my encryption keys stored in a location that’s automatically synced to various personal devices and one off-site location maintained by a trusted party. I have the backups and encryption key sync configured to keep n old versions of the files (where the value of n depends on how critical the file is).
Incremental synchronization really keeps the bandwidth and storage costs down and the amount of data I am backing up makes file level backup a very reasonable option.
If I wanted to back up everything, I would set up a second system off-site and run backups over a secure tunnel.