Sun Cluster 3.0-3.1 Hardware Administration Manual for Solaris OS

SPARC: Complying With Quorum Device Requirements

You must use a quorum device for a two-node cluster. For larger clusters, a quorum device is optional. These are standard cluster requirements.

In addition, you can configure quorum devices to ensure that specific rooms can form a cluster in the event of a failure. For guidelines about where to locate your quorum device, see SPARC: Deciding How to Use Quorum Devices.