My main TimeMachine backup (for my and my wife's MBPs) is over SMB to ZFS (RAIDZ2) on my NAS. Running pretty well for 2 years or so now. The only issues I've ha

My main TimeMachine backup (for my and my wife's MBPs) is over SMB to ZFS (RAIDZ2) on my NAS. Running pretty well for 2 years or so now. The only issues I've had seem to be related to running out of space with the quotas I've set (so I make sure I leave some space for my wife), since the ZFS snapshots prevent the TimeMachine's auto pruning mechanisms from freeing up space like it expects. Thankfully I was always able to ZFS roll back and find a recent a known good snapshot, manually prune old ZFS snapshots to make space, run a Time Machine verification, and keep going (after making a manual "known good" snapshot). Thankfully, I recently discovered the ZFS refquota setting that seems to have resolved the wonky dance above and lets my quotas work as TimeMachine expects (though extra space is used for my ZFS snapshots, which is fine because the TImeMachine stuff is only a small part of the array's storage). The only other issue I've had is with ZFS on arch (kernel upgrades / dkms issuss), so I recently moved to NixOS an it's been solid so far. TimeMachine backups over Tailscale are pretty sweet! Separately, I have a second TimeMachine backup to an AirPort Extreme-attached USB drive. I also use restic for cross-platform backups to the same NAS above, which then sends ZFS snapshots (of the TM + restic data) to a remote server. Finally I have a USB drive in a safe that I manually take out and run a locally-attached TimeMachine backup to every month or so. Keeping everything backed up was a (tongue-in-cheek) part of my wedding vows -- stakes are high.