I also have a ZFS NAS and a separate backup server for the NAS that only gets turned on once a week. I disagree about his recommendation to avoid encryption. I keep the NAS and backup server drives encrypted. It’s not a big deal to unlock the drives at boot with a password and I’ve never had any issues with it. If someone breaks in and steals one of the servers, at least they won’t have access to years of all of my documents backed up.

This author’s setup looks good, but I think most people would get burned out by the complexity unless you really like managing servers, automating things with scripts, and navigating the little quirks that pop up with the hardware and software involved.

A complex solution isn’t necessarily better if you find yourself not investing the time needed to maintain it. I think most people would be better off trusting one of the online backup services rather than spending thousands of dollars building and maintaining a pair of backup servers. If you’re worried about losing data, signing up for two separate backup services could still be cheaper than building and running two separate NAS servers.

Start with easy backup solutions first to get something going. Then consider the more complicated options later.