Shadowing vital containers
I have some critical containers on my home server (mainly Home Assistant and friends) that I can't live without. My whole home and life is dependent on them, lol. I already run RAID1c3 BTRFS, dual UPS and have a backup system in place. But it's impossible to eliminate every possible source of disasters. Especially on a modest budget.
I have an old Intel NUC to use as a shadow server for emergency failover.
Docker Swarm - doesn't handle storage
Kubernetes - apparently can handle storage but I'm told it's difficult.
Bash scripts, SSH, BTRFS snapshots etc. - I'm pretty good at this stuff so it seems like the default approach. Wake the shadow up, update it, test it and send it back to sleep every interval.
What's the right answer?