Understanding Clustering

The following terminology is used throughout this section.

Primary node   The cluster server on which Microsoft Exchange Server is initially installed.

Secondary node   The other server in a cluster server. The secondary node copies information from the primary node during installation and supplemental updates.

Network name resource   The network name of the cluster virtual server. This is the network name accessed by clients connecting to the cluster. This name must be unique within the network.

IP address resource   A static Internet Protocol (IP) address associated with the virtual server's network name. This is the IP address accessed by clients connecting to the cluster. The IP address must be unique within the network.

Virtual server   The network interface presented to the network on behalf of the Microsoft Exchange Server cluster group. A virtual server is a combination of the network name and the IP address resources. All requests to the Microsoft Exchange Server cluster are directed to the virtual server.

Active node   The cluster server that currently owns cluster group resources and responds to network requests made to those services. In a Microsoft Exchange Server cluster environment, only one of the clustered nodes can be active at a given time.

Inactive node   The cluster server that does not currently own cluster group resources but is available if the active node fails over.

Microsoft Exchange Server cluster resource group   A logical grouping of Microsoft Exchange Server cluster resources for the purpose of administration and fail over. For administration, global actions, such as common properties, can be applied to the group as a whole. The Microsoft Exchange Server cluster resource group also provides consistency during fail over because fail over of a cluster group includes all resources of that group.

Dependencies   Many clustered resources are dependent on other resources for operation. Setup creates the dependencies for all resources except the Microsoft Mail Connector. You must create the dependencies for this resource, as described in "Configuring Additional Components" later in this chapter.

Physical disk resource   The disk resource shared between servers in a cluster. The physical disk hosts Microsoft Exchange Server-related files and databases, and is a member of the Microsoft Exchange Server cluster group.

Microsoft Exchange Server resources   Many Microsoft Exchange Server resources can exist within the Microsoft Exchange Server cluster group. Because Microsoft Exchange Server is cluster-aware, these services are automatically created and configured during Setup and configuration of Microsoft Exchange Server into the cluster.