This article describes some of the requirements to support clustering in Microsoft Virtual Server 2005.

Back to the top

Virtual Server 2005 is not a cluster aware program. However, you can store virtual machine disk images on the shared storage location of a server cluster. You can also store virtual machine disk images in any one or more of the following locations:

•	A network-attached storage (NAS) device
•	A Storage Area Network (SAN)
•	An external drive that is connected to a universal serial bus (USB) port
•	An external drive that is connected to an IEEE 1394 port
•	A network drive

Back to the top

Clustering virtual machines

In Virtual Server 2005, you can create a server cluster by using virtual machines. In this scenario, you can configure a simple two-node server cluster, where one virtual machine can fail over to another virtual machine. The following are the requirements and the limitations to support creating a server cluster by using virtual machines in Virtual Server 2005:

•	Virtual Server 2005 supports only a two-node failover server cluster, where one virtual machine can fail over to another virtual machine.
•	The shared storage volume for the server cluster must be a fixed-size virtual hard disk (.vhd).
•	The shared virtual hard disk cannot have the Undo feature enabled.
•	Both virtual machine cluster nodes must be configured on the same physical computer.
•	You must format the shared storage volume with the NTFS file system to support a server cluster.
•	Virtual Server 2005 clustering is only supported on Microsoft Windows Server 2003, Enterprise Edition.

Important Because Virtual Server 2005 clustering is limited to the failover from one virtual machine to another virtual machine, and because both virtual machines must be configured on the same computer, this clustering solution does not protect you against a hardware failure on the host computer. If you want to use this clustering solution in a production environment, Microsoft recommends that you use fault-tolerant devices in your Virtual Server computer.

Note Because Virtual Server 2005 does not support the failover from a virtual machine on one host computer to a virtual machine that resides on a second host computer, a server cluster that you configure in Virtual Server 2005 is best suited for testing and development purposes. Microsoft recommends that you do not use this configuration in a production environment.

Back to the top