@francesco-provino said in Application clustering VS RAID with modern SSD:
There is also the possibility of create TWO drbd replica set, one active on the first node and the other active on the second; that way, I can easily double the total cpu count and ram available for the VMs… sort of hyperconvergency on the cheap!
It's hyperconverged whether you do that or not. HC is free, even with far more robust systems like Starwind. HC doesn't imply that you have HA or can move workloads around. Most people do that, but it's HC from the moment you go with the design here. But DRBD isn't saving you anything over normal baseline. So while this is cheap, it's not special or cheaper, and it's a well known model that under normal circumstances you would never do without local RAID because it's been analyzed heavily for decades and it just doesn't provide a logical protection versus simpler, cheaper approaches.