[ClusterLabs] Antw: Re: [EXT] Re: Two node cluster without fencing and no split brain?

[Andrei Borzenkov]

On Mon, Jul 26, 2021 at 4:53 PM john tillman <johnt at panix.com> wrote:
> >>
> >> Maybe explain how it should work:
> >> If the two nodes cannot rech each other, but each can reach the ping
> >> node,
> >> which node has the quorum then?
> >>
> >
> > Guess both - which is what is played down as 'disadvantage' in the
> > description
> > below ;-)
> >
> >
>
> It is not perfect, I agree, but it may be better than nothing at all.
>
> As for how it worked in my head:
>
> I would have used the switch's IP address as the "ping" tie breaker; a
> common connection point between the two nodes.  My assumption is that if
> there was network loss by Node A then it would lose quorum. In the mean
> time Node B would still reach the switch, achieve quorum, and start/move
> resources.
>

You seriously misunderstand what "split brain" means. Once more - both
nodes are up, neither node can contact another node, both nodes can
ping switch. What should each node do now?