[Linux-HA] two node cluster preventing split brain?

[Andrew Beekhof]

On 7/31/07, Sebastian Reitenbach <sebastia at l00-bugdead-prods.de> wrote:
> Hi list,
>
> I am running heartbeat-2.1.0 on openSUSE 10.2.
> I use to use ssh to the ilo of the servers to stonith them, stonith
> generally works well. I configured the two ilo ip addresses as ping nodes
> in /etc/ha.d/ha.cf. I have a clone set pingd, a clone set stonith, and a
> clone set suicide defined,

what does that mean?

> each with max_clones=2 and max_clone_node=1.
> Stonith is enabled in the cluster.
>
> Now my test scenario:
> - I remove the cables from the ilo boards
>   - the heartbeat correctly detects both as down
> - then I remove the network cables from one host
> Here the split brain situation happens, well, stonith cannot work, as the
> ilo boards are not reachable by any host.
>
> Here my questions:
> Do I can define constraints in the cluster or operations on the suicide
> resource, or pingd resource, so that the actual DC will stay alive, and the
> other node suicides itself?

in a 2 node setup this simply isnt possible.
in a cluster with >2 nodes, you can make use of quorum.
set no-quorum-policy=stop and only if the cluster can form a set with
a majority of the nodes will resources be started.

> How is suicide intended to work?

-ENOSUCHFEATURE