Sun Cluster 3.0-3.1 Hardware Administration Manual for Solaris OS

SPARC: Quorum in Three-Room Configurations

In three-room, two-node campus clusters, you should use the third room for the quorum device (Figure 7–1) or a server (Figure 7–3). Isolating the quorum device gives your cluster a better chance to maintain availability after the loss of one room. If at least one node and the quorum device remain operational, the cluster can continue to operate.