http://bit.ly/1lKJFIa "Cluster group" fail-over will cause cluster go offline. Really? Single point of failure? Am I missing something? What happens when Core Cluster resources (Cluster Group) are failed over from one node to another? Will it take whole cluster down? Thanks.
Yes, if any of the resources in the Cluster Group fail, the cluster will go offline.
No, it is not a single point of failure. The Cluster Name, and IP address are responded to by all nodes in a cluster. If multiple nodes go down, the remaining nodes will attempt to form a quorum and continue responding to requests.
The Quorum resource is only needed when a cluster has an even number of nodes. It is usually the witness disk and is given a tiebreaker vote for quorum. http://technet.microsoft.com/en-us/library/cc731739.aspx