In a bunch of DRBD + Heartbeat, the server falls into Secondary, how to fix it?

Question

System administration

I'm making HA Cluster. I chose a bunch of DRBD + Heartbeat.
In normal mode, everything works, in manual mode, Primary and Secondary are switched. But when the Primary server is turned off, the second one becomes it and falls into Secondary after a while. And, accordingly, the cluster is not available until the first one rises. What could be the problem?

Answer 1

In general, I set everything up from 0 again, and it all worked. I haven't found the cause of the problem yet.