Why does proxmox cluster start with errors when enabling clvm and fence?

Question

Proxmox

I decided to build a cluster on proxmox (version 3.2) with iscsi, of course I installed clvm on top of this. The cluster was configured according to the instructions https://pve.proxmox.com/wiki/Proxmox_VE_2.0_Cluster and https://pve.proxmox.com/wiki/Fencing
After creating the cluster, everything works fine until the fence and clvm are enabled and then rebooted. I use fence_ifmib. The process of isolating nodes goes without problems both manually and by the cluster itself. clvm also starts without problems. VMs are created, they work, I migrate even to a live one.
But as soon as you restart the node or both nodes, problems begin. And there is a quorum, and pvecm nodes on the nodes show that both servers are present, and pvecm status says that everything is OK, and fence_tool ls sees both nodes, and clvm starts. But in the GUI, the pair server is displayed with a red dot. And in the Summary there is no PVECluster for the pair node.
It helps to manually disable the fence, reboot, and re-enter the fence domain.
Z.Y. The IP addresses of the nodes after the creation of the cluster did not change. Both nodes ping each other by name. Multicast is enabled, a group is created, the necessary switch ports fall into it.
Z.Z.Y. Restarting cman doesn't help. Only manual output and reverse input to the fence domain.

Answer 1

There are suspicions that at least 3 nodes are needed for normal operation of the fence.
PS After updating to version 3.3 the problem disappeared