There is a compatibility issue - the virtio_scsi module, required by Nutanix AHV, is not loaded by default with Avaya IP Office Server Edition.
To check if it loads, issue the following from an elevated console login:
lsinitrd | grep virtio | awk '{print $9}'
If the virtio_scsi.ko is missing, then issue the following command to rebuild the initramfs:
dracut --add-drivers "virtio_scsi virtio_pci" -f -v /boot/initramfs- `uname -r`.img `uname -r`
Re-running the first command should now show that the require module is available now.
The VM can now be powered off and exported to be imported into Nutanix AHV. Of course, there are specific steps for this as well.
To most this procedure sounds a bit scary, but it works.