[Pacemaker] Beginner troubles

[Pavlos Parissis]

On 30 November 2010 20:39, Ziri Camden <zcamden at gmail.com> wrote:
>>> Things work great as long as I stick to a 2-node setup with STONITH
>>> disabled and quorum ignored. As soon as I add a third node, things get
>>> odd. The third node isn't seen by the rest of the cluster and doesn't
>>> see its peers.
>>
>> Usually its a firewall.  Are they all connected to the same switch?
>
> Same unmanaged switch, no VLANs or anything. No firewalls on any of
> the clients. Tried several different physical ports on the switch.
> About as simple a setup as is possible.
>
> I have tried setting up the stack in a different order on all three
> physical hosts, and without fail the first two nodes I configure work
> predictably until a third is added. It doesn't seem to matter which
> physical host I use - the last one I set up might see the cluster
> once, then completely loses it when I reboot one of the other nodes
> (and re-start corosync on it).
>
> All this is without any services configured, although services do seem
> to fail over properly in a 2-node configuration.
>
> I'm at a loss. This will be a facepalm moment when I sort it out, I'm sure.

Have you run tcpdump -i any port 5405 on all nodes to verify that they
send and receive cluster messages?