I run a few VMs in a “homelab”. Was interested in redundancy so could work on system without taking down home networking… Familiar with GlusterFS, corosync/pacemaker, etc…
So to go from one system to 2, need a third system to at least ensure quorum.
Of course, storage has the same problem.
Active-active has its complexities. Maybe active-standby good enough with DRND. Still a lot to configure…
Filesystem replication now means my NVMe drives will be limited to 1Gbit/s networking link. 10GB somewhat difficult on SFF PC and expensive.
Physical location also matters. Standby probably should be somewhere else… But what about 3rd node? Wired networking not everywhere…
This ends up being a lot of moving parts, expense, and headache…
Guess what is fast? Single node. Move the storage drive to similar spare SFF PC. Two screws, takes about 3 minutes max. Local RAID-1 to guard against sudden failure… Backup a couple times a year for peace of mind.
It’s way too easy to overthink stuff…