Configure a Virtual Machine for High Availability

Applies To: Windows Server 2008, Windows Virtualization

A highly available virtual machine requires that you perform some specific configuration and tasks. Some configuration and tasks must be done before you make the virtual machine highly available, while others must be done afterward. Before you try to make a virtual machine highly available, review the following information to make sure that the virtual machine is configured appropriately.

Before you make the virtual machine highly available

Before you make the virtual machine highly available, you need to review, and in some cases, modify the networking, security, and storage in your environment.

• Networking. All nodes in the same cluster must use the same name for the virtual network that provides external networking for the virtual machines. For example, if you created a virtual network through the Add Roles Wizard when you installed the role, a name is assigned to the virtual network based on the network adapter. This name will be different on each physical computer. You must delete the virtual network and then recreate it, using the same name on each physical computer in the cluster. Also note that if a physical network adapter uses static settings, such as a static IP address, and IPv6 is not disabled, the static settings will be deleted when you connect a virtual network to the physical adapter. In that case, you must reconfigure the static settings.

• Security. To avoid potential problems you might encounter trying to administer highly available virtual machines, all nodes in the cluster must use the same authorization policy. There are two ways you can accomplish this:

  • Use a local, XML-based authorization store on each node. The policy must be configured the same on each store in the cluster.

  • Use an authorization store located in Active Directory.

• Storage. You must use shared storage that is supported by both the Failover Clustering feature and Hyper-V™. When you create the virtual machine, choose the option to store the virtual machine in a new folder and specify the location of the shared storage.

Note

The virtual machine must be turned off so that you can make it highly available. To make a virtual machine highly available, you run the High Availability wizard from the Failover Cluster Management snap-in and select Virtual Machine as the service or application to make highly available.

After you make the virtual machine highly available

After you make the virtual machine highly available, do the following:

• Install the guest operating system and the integration services. For instructions, see Install a Guest Operating System.

• Configure the virtual machine to take no action through Hyper-V if the physical computer shuts down by modifying the Automatic Stop Action setting to None. Virtual machine state must be managed through the Failover Clustering feature. For more information about the setting, see Virtual Machine Settings.

• Before you shut down a virtual machine that is highly available, you must take the virtual machine resource offline. From the Failover Management snap-in, navigate to the virtual machine resource. Right-click Properties and then click the Offline Actions tab. Choose the appropriate action and then take the virtual machine resource offline.

Important

Changing the offline action affects the behavior of the virtual machine if a failover occurs. For example, if you choose a shutdown action and a failover occurs, the virtual machine will shut down instead of fail over to another node.

If you use snapshots on a clustered virtual machine, all resources associated with each snapshot must be stored on the same shared storage as the virtual machine.

Additional considerations

• By default, membership in the local Administrators group, or equivalent, is the minimum required to complete this procedure. However, an administrator can use Authorization Manager to modify the authorization policy so that a user or group of users can complete this procedure.