Before implementing GroupWise 8 in a Microsoft cluster, make sure you have a solid understanding of Microsoft clustering technologies by reviewing the following information resources:
When you review the information resources recommended above, you discover that clustering employs very specialized terminology. The following brief glossary provides basic definitions of clustering terms and relates them to your GroupWise system:
cluster: A grouping of from two to eight Windows servers configured so that data storage locations and applications can transfer from one server to another without interrupting their availability to users.
node: A clustered server; in other words, a single Windows server that is part of a cluster.
active node: A node in the cluster that is actively running programs. An active node makes its resources available in the cluster.
passive node: A node in the cluster that is not currently running programs, but is waiting for an active node to fail. A passive node does not make its resources available in the cluster until an active node fails over to it.
resource: A data storage location or application. For example, a domain directory and the MTA for the domain are resources. A post office directory and the POA for the post office are resources.
resource group: Two or more resources that must fail over together in order to remain functional. For example, for a domain to be functional, the domain directory and its MTA must fail over together. For a post office to be functional, the post office directory and its POA must fail over together
physical disk: The physical location where resources are created or installed. For example, a domain or post office directory is created on a physical disk. The agent software is installed on a physical disk.
shared disk: A physical disk that can be made active on any node in the cluster.
failover: The process of moving resources and resource groups on a shared disk from a failed node to a functional node so that availability to users is uninterrupted. For example, if the node where the POA is running goes down, the post office resource group would fail over to another node so that users could continue to use GroupWise.
fan-out-failover: The configuration where resources and resource groups from a failed node fail over to different nodes in order to distribute the load from the failed node across multiple nodes in the cluster. For example, if a node runs a resource group consisting of a domain and its MTA, another resource group consisting of a post office and its POA, and a third resource group for WebAccess, each resource group could be configured to fail over separately to different nodes in the cluster.
failback: The process of returning resources and resource groups to their original node after the situation causing the failover has been resolved. For example, if a POA and its post office fail over to another node in the cluster, that resource group can be configured to fail back to its original node when the problem is resolved.
shared disk system: The hardware housing the physical disks that are shared among the nodes in the cluster. The C: drives in the clustered nodes are not part of the shared disk system. Each C: drive belongs to its own server.
storage area network (SAN): The clustered nodes together with their shared disk system and shared physical disks.