I originally posted this on reddit, but I'm happy to see it reposted elsewhere. Let me know if anyone has any questions.

That's a huge setup :)

One questions I have regarding NAS is backups of the NAS itself.

If I have a very simple NAS with 2 drives in Raid 1 (let's call it Drive A and B), and I want to make a physical backup of my NAS in a different location. How easy is it ? What is the best practice. Ideally you could just have a big rsync method that takes care of it, or rclone as described in the article, but what if you want to do it without any network transfer (because your connection is too slow/ you can't afford it)

Does the following protocol make sense: Removing Drive A , replacing it with an empty drive C. Wait for the NAS to synchronize drive C. Then remove Drive B, replace with drive D, wait for the NAS to synchronize drive D.

Taking Drive A and B to a different location, plug them, and have the backup working out of the box.

Is it that easy? What about more complicated RAID setups?

is there an easy "Prepare Backup -> Please insert First drive for your backup -> First drive filled up -> please insert second drive for your backup -> ... -> Please insert last drive for your backup" and then you take all those newly filled drives and shove them in a different box and they have all the data at the time of the backup, with either the right zfs and raid configuration, or at least a simple data dump in a non-raid configuration.

Refreshing the backups is either done by putting the backups online at the remote location and syncing the deltas between the last snapshot and the current over the net, or by bringing the drives back to the primary, and sending the deltas.

The sanoid/syncoid toolset will help immensely with handing the necessary zfs snapshot and send/receive commands: https://github.com/jimsalterjrs/sanoid