If the Solaris Volume Manager metadbs lose replica quorum for a diskset on a cluster node, the volume manager panics the cluster node. Sun Cluster then takes over the diskset on a surviving node and your application fails over to a secondary node.
To ensure that the node panics and is fenced off if it loses its connection to shared storage, configure each metaset with at least two disks. In this configuration, the metadbs stored on the disks create their own replica quorum for each diskset.
Dual-string mediators are not supported in Solaris Volume Manager configurations that use a single dual-port HBA. Using dual-string mediators prevents the service from failing over to a new node.
When configuring Solaris Volume Manager metasets, ensure that each metaset contains at least two disks. Do not configure dual-string mediators.
When a dual-port HBA fails with both ports in this configuration, the cluster behavior depends on whether the affected node is primary for the diskset.
If the affected node is primary for the diskset, Solaris Volume Manager panics that node because it lacks required state database replicas. Your cluster reforms with the nodes that achieve quorum and brings the diskset online on a new primary node.
If the affected node is not primary for the diskset, your cluster remains in a degraded state.
Follow the instructions for replacing an HBA in your storage device documentation.