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.
  
  
• Processor. If the nodes in your cluster use different processor versions, make sure that you configure the virtual machine for processor compatibility. This helps ensure that you can failover or migrate a virtual machine without encountering problems due to different virtualization features on different versions of the same manufacturer’s processor. However, this does not provide compatibility between different processor manufacturers.
  
  
• 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 Domain Services (AD DS).
    
    
• 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. For more information about cluster storage, see Failover Clusters (http://go.microsoft.com/fwlink/?LinkID=143559).
  
  

	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, 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.
  
  
• 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.
  
  
• If you change the configuration of a virtual machine, we recommend that you use the Failover Manager snap-in to access the virtual machine settings. When you do this, the cluster is updated automatically with the configuration changes. However, if you make changes to the virtual machine settings from the Hyper-V Manager snap-in, you must update the cluster manually after you make the changes. If the configuration is not refreshed after networking or storage changes are made, a subsequent failover may not succeed or may succeed but result in the virtual machine being configured incorrectly.
  
  

	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.

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. For more information, see Using Authorization Manager for Hyper-V Security (http://go.microsoft.com/fwlink/?LinkId=142886).
  
  

Additional references

• Checklist: Configure Virtual Machines for High Availability
  
  
• Configuring Virtual Machines