Product specifications

Clustering Technology and Terminology

Clustering is not always straightforward, so it is important that you get familiar with the

technology and terminology of failover clusters before you start. A good source of information is

the Windows Server 2008 R2 Failover Clustering resource site:

www.microsoft.com/windowsserver2008/en/us/failover-clustering-technical.aspx

The following link describes the role of the quorum in a cluster:

http://technet.microsoft.com/en-us/library/cc770620(WS.10).aspx

Here is a brief summary of the major concepts and terms:

• Nodes: Individual computers in a cluster configuration.

• Cluster service: A Windows service that provides the cluster functionality. When this service

is stopped, the node appears offline to other cluster nodes.

• Resource: Cluster components (hardware and software) that are managed by the cluster

service. Resources are physical hardware devices such as disk drives, and logical items such

as IP addresses and applications.

• Online resource: A resource that is available and is providing its service.

• Quorum: A special common cluster resource. This resource plays a critical role in cluster

operations.

• Resource group: A collection of resources that are managed by the cluster service as a

single, logical unit and that are always brought online on the same node.