[Ocfs2-users] About quorum and fencing

[Gil]

Hi,

In the ocfs2 FAQ, it is written:

"A node has quorum when:
      * it sees an odd number of heartbeating nodes and has network
        connectivity to more than half of them.
        OR,
      * it sees an even number of heartbeating nodes and has network
        connectivity to at least half of them *and* has connectivity to
        the heartbeating node with the lowest node number."

So if I turn off the switch in a two node cluster, each node will see
two nodes heatbeating and will also see that it has connectivity to half
of them (itself). The one with lowest node number will fullfil the
quorum condition and stay alive. The other one will fence.

If I have a three node cluster, however, and turn off the interconnect
switch, none of my nodes will fullfil the quorum condition (none of them
will see more than half the nodes that are heartbeating) and they will
all fence.

A three node cluster would be less reliable than a two node one. I would
expect that at least one of the nodes would survive in _any_ situation.

I'm I missing any part of the picture?

Best regards,
    Gil