Messaging Server requires Directory Server, but not necessarily a local copy. You will need the Sun Cluster Core component as well as the Sun Cluster Agents for Directory Server and Messaging Server. If a remote Directory Server is used, then the Sun Cluster Agent for Directory Server is not required.
Installing, configuring, and starting the product components in the correct order is crucial for a successful Sun Cluster implementation.
Installing the Sun Cluster product component
Configuring the Sun Cluster framework
Installing the additional product components that are required for Messaging Server to operate in the cluster
Configuring the Sun Cluster data services using the agents for the relevant product components
At least two installation sessions are performed on each node in the cluster.