As seen in log below libxenlight driver does not get loaded for virt-type: xen.
nova-compute-xen:
charm: "cs:~openstack-charmers-next/xenial/nova-compute"
series: xenial
num_units: 3
options:
enable-live-migration: true
enable-resize: true
migration-auth-type: ssh
virt-type: xen
openstack-origin: cloud:xenial-newton
Log:
ubuntu@node07ob200:/var/log/nova$ sudo tail -f nova-compute.log
2017-06-06 14:49:31.782 26748 ERROR oslo_service.service File "/usr/lib/python2.7/dist-packages/nova/virt/libvirt/driver.py", line 465, in init_host
2017-06-06 14:49:31.782 26748 ERROR oslo_service.service self._do_quality_warnings()
2017-06-06 14:49:31.782 26748 ERROR oslo_service.service File "/usr/lib/python2.7/dist-packages/nova/virt/libvirt/driver.py", line 443, in _do_quality_warnings
2017-06-06 14:49:31.782 26748 ERROR oslo_service.service caps = self._host.get_capabilities()
2017-06-06 14:49:31.782 26748 ERROR oslo_service.service File "/usr/lib/python2.7/dist-packages/nova/virt/libvirt/host.py", line 662, in get_capabilities
2017-06-06 14:49:31.782 26748 ERROR oslo_service.service xmlstr = self.get_connection().getCapabilities()
2017-06-06 14:49:31.782 26748 ERROR oslo_service.service File "/usr/lib/python2.7/dist-packages/nova/virt/libvirt/host.py", line 420, in get_connection
2017-06-06 14:49:31.782 26748 ERROR oslo_service.service raise exception.HypervisorUnavailable(host=CONF.host)
2017-06-06 14:49:31.782 26748 ERROR oslo_service.service HypervisorUnavailable: Connection to the hypervisor is broken on host: node07ob200
2017-06-06 14:49:31.782 26748 ERROR oslo_service.service
2017-06-06 14:53:30.239 28643 WARNING oslo_reports.guru_meditation_report [-] Guru meditation now registers SIGUSR1 and SIGUSR2 by default for backward compatibility. SIGUSR1 will no longer be registered in a future release, so please use SIGUSR2 to generate reports.
2017-06-06 14:53:30.393 28643 WARNING os_brick.initiator.connectors.remotefs [req-87a24a36-0b3f-4c9a-bf16-194878c62d79 - - - - -] Connection details not present. RemoteFsClient may not initialize properly.
2017-06-06 14:53:30.394 28643 WARNING oslo_config.cfg [req-87a24a36-0b3f-4c9a-bf16-194878c62d79 - - - - -] Option "rabbit_virtual_host" from group "oslo_messaging_rabbit" is deprecated for removal. Its value may be silently ignored in the future.
2017-06-06 14:53:30.395 28643 WARNING oslo_config.cfg [req-87a24a36-0b3f-4c9a-bf16-194878c62d79 - - - - -] Option "rabbit_host" from group "oslo_messaging_rabbit" is deprecated for removal. Its value may be silently ignored in the future.
2017-06-06 14:53:30.395 28643 WARNING oslo_config.cfg [req-87a24a36-0b3f-4c9a-bf16-194878c62d79 - - - - -] Option "rabbit_userid" from group "oslo_messaging_rabbit" is deprecated for removal. Its value may be silently ignored in the future.
2017-06-06 14:53:30.396 28643 WARNING oslo_config.cfg [req-87a24a36-0b3f-4c9a-bf16-194878c62d79 - - - - -] Option "rabbit_password" from group "oslo_messaging_rabbit" is deprecated for removal. Its value may be silently ignored in the future.
2017-06-06 14:53:30.438 28643 WARNING oslo_config.cfg [req-87a24a36-0b3f-4c9a-bf16-194878c62d79 - - - - -] Option "api_paste_config" from group "DEFAULT" is deprecated. Use option "api_paste_config" from group "wsgi".
2017-06-06 14:53:30.442 28643 WARNING oslo_config.cfg [req-87a24a36-0b3f-4c9a-bf16-194878c62d79 - - - - -] Option "vnc_enabled" from group "DEFAULT" is deprecated. Use option "enabled" from group "vnc".
2017-06-06 14:53:30.443 28643 WARNING oslo_config.cfg [req-87a24a36-0b3f-4c9a-bf16-194878c62d79 - - - - -] Option "vnc_keymap" from group "DEFAULT" is deprecated. Use option "keymap" from group "vnc".
2017-06-06 14:53:30.443 28643 WARNING oslo_config.cfg [req-87a24a36-0b3f-4c9a-bf16-194878c62d79 - - - - -] Option "novncproxy_base_url" from group "DEFAULT" is deprecated. Use option "novncproxy_base_url" from group "vnc".
2017-06-06 14:53:30.444 28643 WARNING oslo_config.cfg [req-87a24a36-0b3f-4c9a-bf16-194878c62d79 - - - - -] Option "vncserver_listen" from group "DEFAULT" is deprecated. Use option "vncserver_listen" from group "vnc".
2017-06-06 14:53:30.444 28643 WARNING oslo_config.cfg [req-87a24a36-0b3f-4c9a-bf16-194878c62d79 - - - - -] Option "vncserver_proxyclient_address" from group "DEFAULT" is deprecated. Use option "vncserver_proxyclient_address" from group "vnc".
2017-06-06 14:53:30.475 28643 WARNING nova.virt.libvirt.driver [req-641aa21f-dab3-4979-aaf0-d7c2ae60a56f - - - - -] Cannot update service status on host "node07ob200" since it is not registered.
2017-06-06 14:53:30.476 28643 ERROR nova.virt.libvirt.host [req-641aa21f-dab3-4979-aaf0-d7c2ae60a56f - - - - -] Connection to libvirt failed: internal error: libxenlight state driver is not active
2017-06-06 14:53:30.476 28643 ERROR nova.virt.libvirt.host Traceback (most recent call last):
2017-06-06 14:53:30.476 28643 ERROR nova.virt.libvirt.host File "/usr/lib/python2.7/dist-packages/nova/virt/libvirt/host.py", line 411, in get_connection
2017-06-06 14:53:30.476 28643 ERROR nova.virt.libvirt.host conn = self._get_connection()
2017-06-06 14:53:30.476 28643 ERROR nova.virt.libvirt.host File "/usr/lib/python2.7/dist-packages/nova/virt/libvirt/host.py", line 398, in _get_connection
2017-06-06 14:53:30.476 28643 ERROR nova.virt.libvirt.host wrapped_conn = self._get_new_connection()
2017-06-06 14:53:30.476 28643 ERROR nova.virt.libvirt.host File "/usr/lib/python2.7/dist-packages/nova/virt/libvirt/host.py", line 350, in _get_new_connection
2017-06-06 14:53:30.476 28643 ERROR nova.virt.libvirt.host wrapped_conn = self._connect(self._uri, self._read_only)
2017-06-06 14:53:30.476 28643 ERROR nova.virt.libvirt.host File "/usr/lib/python2.7/dist-packages/nova/virt/libvirt/host.py", line 204, in _connect
2017-06-06 14:53:30.476 28643 ERROR nova.virt.libvirt.host libvirt.openAuth, uri, auth, flags)
2017-06-06 14:53:30.476 28643 ERROR nova.virt.libvirt.host File "/usr/lib/python2.7/dist-packages/eventlet/tpool.py", line 144, in proxy_call
2017-06-06 14:53:30.476 28643 ERROR nova.virt.libvirt.host rv = execute(f, *args, **kwargs)
2017-06-06 14:53:30.476 28643 ERROR nova.virt.libvirt.host File "/usr/lib/python2.7/dist-packages/eventlet/tpool.py", line 125, in execute
2017-06-06 14:53:30.476 28643 ERROR nova.virt.libvirt.host six.reraise(c, e, tb)
2017-06-06 14:53:30.476 28643 ERROR nova.virt.libvirt.host File "/usr/lib/python2.7/dist-packages/eventlet/tpool.py", line 83, in tworker
2017-06-06 14:53:30.476 28643 ERROR nova.virt.libvirt.host rv = meth(*args, **kwargs)
2017-06-06 14:53:30.476 28643 ERROR nova.virt.libvirt.host File "/usr/lib/python2.7/dist-packages/libvirt.py", line 105, in openAuth
2017-06-06 14:53:30.476 28643 ERROR nova.virt.libvirt.host if ret is None:raise libvirtError('virConnectOpenAuth() failed')
2017-06-06 14:53:30.476 28643 ERROR nova.virt.libvirt.host libvirtError: internal error: libxenlight state driver is not active
2017-06-06 14:53:30.476 28643 ERROR nova.virt.libvirt.host
2017-06-06 14:53:30.478 28643 ERROR oslo_service.service [req-641aa21f-dab3-4979-aaf0-d7c2ae60a56f - - - - -] Error starting thread.
2017-06-06 14:53:30.478 28643 ERROR oslo_service.service Traceback (most recent call last):
2017-06-06 14:53:30.478 28643 ERROR oslo_service.service File "/usr/lib/python2.7/dist-packages/oslo_service/service.py", line 708, in run_service
2017-06-06 14:53:30.478 28643 ERROR oslo_service.service service.start()
2017-06-06 14:53:30.478 28643 ERROR oslo_service.service File "/usr/lib/python2.7/dist-packages/nova/service.py", line 117, in start
2017-06-06 14:53:30.478 28643 ERROR oslo_service.service self.manager.init_host()
2017-06-06 14:53:30.478 28643 ERROR oslo_service.service File "/usr/lib/python2.7/dist-packages/nova/compute/manager.py", line 1140, in init_host
2017-06-06 14:53:30.478 28643 ERROR oslo_service.service self.driver.init_host(host=self.host)
2017-06-06 14:53:30.478 28643 ERROR oslo_service.service File "/usr/lib/python2.7/dist-packages/nova/virt/libvirt/driver.py", line 465, in init_host
2017-06-06 14:53:30.478 28643 ERROR oslo_service.service self._do_quality_warnings()
2017-06-06 14:53:30.478 28643 ERROR oslo_service.service File "/usr/lib/python2.7/dist-packages/nova/virt/libvirt/driver.py", line 443, in _do_quality_warnings
2017-06-06 14:53:30.478 28643 ERROR oslo_service.service caps = self._host.get_capabilities()
2017-06-06 14:53:30.478 28643 ERROR oslo_service.service File "/usr/lib/python2.7/dist-packages/nova/virt/libvirt/host.py", line 662, in get_capabilities
2017-06-06 14:53:30.478 28643 ERROR oslo_service.service xmlstr = self.get_connection().getCapabilities()
2017-06-06 14:53:30.478 28643 ERROR oslo_service.service File "/usr/lib/python2.7/dist-packages/nova/virt/libvirt/host.py", line 420, in get_connection
2017-06-06 14:53:30.478 28643 ERROR oslo_service.service raise exception.HypervisorUnavailable(host=CONF.host)
2017-06-06 14:53:30.478 28643 ERROR oslo_service.service HypervisorUnavailable: Connection to the hypervisor is broken on host: node07ob200
2017-06-06 14:53:30.478 28643 ERROR oslo_service.service
Xen support is 100% untested so I'm not surprised that this does not actually work.