DRBD is failover - there is an interruption while the switch is made. High availability is when you can afford to lose one or more nodes, and there is no servi

DRBD is failover - there is an interruption while the switch is made. High availability is when you can afford to lose one or more nodes, and there is no service interruption. Moreover, the processing and I/O are symmetric and performance scales linearly by adding more nodes.