Sun Cluster Concepts Guide for Solaris OS

Quorum in Greater Than Two–Node Configurations

It is valid to configure a greater than two-node cluster without a quorum device. However, if you do so, you will not be able start the cluster without a majority of nodes in the cluster.

Illustration: Config1: NodeA-D. A/B connect to (->) QD1. C/D -> QD2. Config2: NodeA-C. A/C -> QD1. B/C -> QD2. Config3: NodeA-C -> one QD.