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Hyper-V: Step-by-Step Guide to Using Live Migration in Windows Server 2008 R2

This guide details the steps required to perform a live migration of Hyper-V™ virtual machines from one node in a Windows Server® 2008 R2 failover cluster to another node.windows-server-2008-r2-logo

Live migration overview

Live migration is a new Hyper-V feature in Windows Server 2008 R2, which requires the failover clustering role to be added and configured on the servers running Hyper-V. Live migration allows you to transparently move running virtual machines from one node of the failover cluster to another node in the same cluster without a dropped network connection or perceived downtime. In addition, failover clustering requires shared storage for the cluster nodes. This can include an iSCSI or Fiber-Channel Storage Area Network (SAN). All virtual machines are stored in the shared storage area, and the running virtual machine state is managed by one of the nodes. For a detailed overview of live migration and the benefits of using it, see Windows Server 2008 R2 Hyper-V Live Migration.

Considerations before using live migration

This guide assumes you are familiar with the requirements for using Hyper-V and failover clustering, which are covered in Hyper-V Step-by-Step Guide: Hyper-V and Failover Clustering.

Specific recommendations to consider before using live migration are listed below:

  • For each node of the failover cluster: use more than one network adapter; configure at least one network adapter for the private virtual network. We recommend that you configure a dedicated private network with Gigabit speed for live migration traffic. This network should be separate from the network for managing the failover cluster, from the network for the virtual machine, and from the network for storage.
  • We recommend that you make the hardware and system settings of the nodes in the failover cluster as similar as possible to minimize potential problems.
  • If possible, do not apply IPSec policies on a private network for live migration because this can significantly impact the performance of live migration.
  • Ensure that the source and destination nodes (for the live migration) in the failover cluster are connected through the same IP subnet. This is so the virtual machine can retain the same IP address after live migration.
  • Before reverting a clustered virtual machine back to a snapshot, you should first shut down the virtual machine from Failover Cluster Manager, take a snapshot of the virtual machine, and restart the virtual machine.
  • When creating the virtual machine, we recommend that you configure the storage location under SystemRoot/ClusterStorage in the Cluster Shared Volumes.

Processor compatibility

Hyper-V provides processor compatibility settings to make it easier to perform a live migration of a virtual machine to another physical computer with a different processor version. The Migrate to a physical computer with a different processor version setting in Hyper-V Manager allows you to move a running virtual machine to a physical computer with different processor features without restarting the virtual machine. It is recommended that you enable this setting to ensure that the virtual machine uses only the features of the processor that are available on all versions of a virtualization-capable processor by the same processor manufacturer. It does not provide compatibility between different processor manufacturers. When this setting is not used, Hyper-V provides the virtual machine with all the virtualization features offered by the physical processor. The setting is also useful for high availability and backup and recovery scenarios because it makes it easier to move a highly available virtual machine to another node in a cluster or restore the virtual machine to different hardware.