Ok, that did not directly come to mind to be honest, but it is very understandable at the moment.
Our customers when migrating away from Hyper-V or VMware environments usually do this when they need to replace their hardware after 5-8 years.
In...
I am a little confused by your response so just checking if we are on the same level here...
You can set up like for example:
PVE01 > Hypervisor, packages for qnetdevice, LINBIT packages, ...
PVE02 > Hypervisor, packages for qnetdevice, LINBIT...
Why don't you look into LINBIT / Linstor (DRBD)? > https://linbit.com/blog/linstor-setup-proxmox-ve-volumes/
It's pretty easy to setup if you need a 2 cluster setup and have small device for quorum, we combine this quorum with Proxmox Backup Server.