Quorum Devices

Sun Cluster configurations use quorum devices to maintain data and resource integrity. If the cluster temporarily loses connection to a node, the quorum device prevents amnesia or split-brain problems when the cluster node attempts to rejoin the cluster. You assign quorum devices by using the scsetup(1M) utility.

You do not need to configure quorum devices for a single-node cluster.

Consider the following points when you plan quorum devices.

• Minimum – A two-node cluster must have at least one shared disk assigned as a quorum device. For other topologies, quorum devices are optional.

• Odd-number rule – If more than one quorum device is configured in a two-node cluster, or in a pair of nodes directly connected to the quorum device, configure an odd number of quorum devices. This configuration ensures that the quorum devices have completely independent failure pathways.

• Connection – You must connect a quorum device to at least two nodes.

For more information about quorum devices, see the Sun Cluster 3.1 10/03 Concepts Guide.