AHV Hypervisor impersonates Hyper-V

One of the first discoveries I made with AHV was the impersonation functionality. I came across this as we began deploying qcow images for Infoblox. Infoblox noted in their documentation that some acli commands were required to be applied to the vm's. So what does this even mean?

AHV hypervisor impersonates as Hyper-V to user VMs. This is important for Windows VMs as in such cases they can take advantage of Hyper-V enlightenments, which improve VM performance.

In the case of Infoblox, this impersonation causes issues with their custom image files. To disable this functionality, you must run the following commands on each VM.

1. Connect to the Cluster IP via SSH.
2. Power off the VM.

nutanix@cvm:~$ acli vm.off <vm name or uuid>

3. Disable branding and enlightenments to the vm.

nutanix@cvm:~$ acli vm.update <vm name or uuid> disable_branding=True
nutanix@cvm:~$ acli vm.update <vm name or uuid> extra_flags="enable_hyperv_stimer=off;enable_hyperv_synic=off;enable_hyperv_vapic=off;enable_hyperv_relaxed=off;enable_hyperv_spinlocks=off;enable_hyperv_clock=False"

For more details on AHV impersonation, check out Nutanix KB 8805.