A. Windows Server 2008 R2 introduced the zero downtime Live Migration technology to migrate VMs from one Hyper-V R2 server to another. When a cluster node is shut down, all the groups/resources on the node are placed in an offline state. For each VM, a setting is configured that specifies what the VM should do if the VM's resource goes offline, as shown below. The default setting is to save the VM's state.



This saving of state in the event of moving the resource to another node is essentially the equivalent of a quick migration, which is the process of saving the memory and state of a VM to disk and then reading it back from disk on the target node.

If you want to use Live Migration to move VMs between nodes when a node shuts down for maintenance, you should investigate a technology such as System Center Virtual Machine Manager (VMM). VMM has a node maintenance feature that uses Live Migration instead of Quick Migration to move VMs. An alternative would be to script your own solution that uses the Move-ClusterVirtualMachineRole PowerShell cmdlet to move the VMs between nodes one at a time (because you can only perform one live migration at a time).

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