(if that service goes down, everyone in my house gets mad at me)

I bought a PiZero and set it up as a redundant pihole for this reason. It’s slower because it’s wireless, but not super noticeable since it’s ‘just’ DNS. I have the router pointed at the main and backup all the time and if I need to do something (or break the main one messing with dockers) there’s still the backup until I get the main up.

I messed around with some High Availability configs where they both had the ‘same’ ip but could never get it working smoothly. I just use the teleporter functionality within pihole any time I update anything to keep them in sync, which is rare.