Well there’s software that can make it easier. Just an option. For ZFS specifically there’s zfs_autobackup which I’ve got experience with and I haven’t tried this but just found out about a Web UI that works with it: https://github.com/natankeddem/bale

Modern filesystems like ZFS have snapshots and the ability to incrementally copy those around even over the network. I’d suggest considering using those instead of something that operates on top of the filesystem.

You don’t because everything here’s based on communities while Mastodon is on individual users. If you’d like something that does both in a single platform I think Mbin would be the best bet (although you can interact with Lemmy communities using Mastodon and other microblogging platforms to some extent)

Another vote for NeoDB. It’s been very useful for me and more people on fedi need to know about it.