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We have existing Hyper-V cluster with Windows 2008 R2 and have recently begun creating a new Hyper-V cluster with Windows Server 2012. We recently added a Dell PowerEdge R710 that previously co-existed in a cluster running 2008 R2 Hyper-V. We are now unable to live migrate to/from this new node with the error below. Using CPU-Z, we find that 'AES' is the only cpu instruction that differs between the systems; existing and new.

Without turning on CPU Compatibility for the VM, is there a way to work around this or possibly disable AES on the CPUs that are capable in the cluster. We are not using secure migrations.

The virtual machine 'Bartender10' is using processor-specific features not supported on physical computer 'HYPERVC4N5'. To allow for migration of this virtual machine to physical computers with different processors, modify the virtual machine settings to limit the processor features used by the virtual machine. (Virtual machine ID 80A6ED64-A8D5-4FF9-959F-61E7F57AB137)

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As a workaround, only start VM's on the other hosts. Then live migrate to your new host. – longneck Feb 12 '13 at 18:36
This does work - and I have tested this to be true. However, this does not pan out in a production environment. If a node fails and everything fails over, or VMs get rebooted over time we're back to square one with the VMs locked down to a specific set of nodes. Thanks, – dmohlmaster Feb 12 '13 at 18:52
in a production environment, you should be running identical equipment. – longneck Feb 12 '13 at 18:53
Perhaps you could disable AES-NI in your other systems' BIOS or UEFI configuration. – Michael Steele Feb 13 '13 at 16:59
One of the great features of Hyper V is it's tolerance of dissimilar hardware which proves to be a killer feature when compared with VMware's extremely picky hardware requirements. I am not saying it will be fully supported but I have run Hyper V Clusters made of such dissimilar hardware has Dell 2960, R610, R710, R810, R900, Cisco UCS B200, and B230 servers. If you have a dissimilar processor family you will hit the expected limitations of live migration only between systems with procs of the same family but this has allowed us to increase our Hyper Visor resources without replacing servers. – Chris Magnuson Feb 19 '13 at 16:49
up vote 1 down vote accepted

Thank you for the direction. I was searching for the AES option in the bios documentation as well as in our Cisco B-series blade bios policies but turned up with nothing. After finally rebooting and walking through the bios of each of the machines in the cluster, I was able to find the setting for 'AES-NI Control' which in turn allowed me to disable. There is still one Dell R610 that will not allow me to flip this option to Disabled, but that his another issue I am going to work on. I am now able to live migrate all VMs between nodes in the Server 2012 cluster without issue.


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