GroupWise Messenger does not require the existence of a GroupWise system in the cluster, but presumably one has already been set up as described in Planning GroupWise in a Linux Cluster and Creating a New GroupWise System to Work with OES Cluster Services. As part of the process of setting up GroupWise in the cluster, you filled out the System Clustering Worksheet. Some of the information from that worksheet is helpful as you implement Messenger in your cluster.