one of our cluster nodes (OES2 SP0, Linux, 2-node-cluster) just
restarted, logging the following into the message file:

CLUSTER-<FATAL>-<6091>: This node [(name)] died.
At least one of the nodes is Alive in the old master's node partition.
This node is NOT in the old master's node partition.

I can not find information about this error code (6091) or how to check
why the node died (from NCS's perspective).

There is a chance that the problem was been caused by a problem with a
network switch (but not the one the servers are directly connected to),
but I like to check this.

Thanks in advance,