There was a dicusssion about memory causing split brain for a 2 nodes RAC; however, the log shows otherwise.
By no means, am I a RAC expert.
For testing purpose, ethernet for cluster_interconnect was shut down.
From ocssd.trc, it does look to be caused by cluster_interconnect when comparing errors from actual vs test.
Details from Google Doc below.
Cluster Interconnect Split Brain Testing
What do you think?
