High-availability clusters

Been reading up on the high-availability clusters feature that we're using in Windows Server 2008.

Failover Clustering is a feature which gives high-availability to services and applications.

High-availability clusters (also known as HA Clusters or Failover Clusters) are computer clusters that are implemented primarily for the purpose of providing high availability of services which the cluster provides. They operate by having redundant computers or nodes which are then used to provide service when system components fail. Normally, if a server with a particular application crashes, the application will be unavailable until someone fixes the crashed server. HA clustering remedies this situation by detecting hardware/software faults, and immediately restarting the application on another system without requiring administrative intervention, a process known as Failover. As part of this process, clustering software may configure the node before starting the application on it. For example, appropriate file systems may need to be imported and mounted, network hardware may have to be configured, and some supporting applications may need to be running as well.

HA Clusters are used in:
- critical databases
- file sharing on a network
- business applications
- customer services such as electronic commerce websites

Steps to install failover cluster feature
1. If you recently installed Windows Server 2008, the Initial Configuration Tasks interface is displayed. Under Customize This Server, click Add features. Then skip to step 3.
2. If the Initial Configuration Tasks interface is not displayed and Server Manager is not running, click Start, click Administrative Tools, and then click Server Manager. (If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue.)
In Server Manager, under Features Summary, click Add Features.
3. In the Add Features Wizard, click Failover Clustering, and then click Install.
4. Follow the instructions in the wizard to complete the installation of the feature. When the wizard finishes, close it.
5. Repeat the process for the second server.

Some additional information about failover clusters:
Requirements for failover clusters:
http://technet.microsoft.com/en-us/library/cc771404.aspx

Hyper-V Step-by-Step Guide: Hyper-V and Failover Clustering:
http://technet.microsoft.com/en-us/library/cc732181.aspx