nova-compute.log
2019-05-13 13:22:34.721 56943 WARNING nova.virt.libvirt.driver [req-897d35c9-a2fb-4529-91f4-0f35497a2911 - - - - -] Cannot update service status on host "ubuntu-bionic-rax-ord-0006119270" since it is not registered.: nova.exception_Remote.ComputeHostNotFound_Remote: Compute host ubuntu-bionic-rax-ord-0006119270 could not be found.
2019-05-13 13:22:34.722 56943 DEBUG nova.virt.libvirt.volume.mount [req-897d35c9-a2fb-4529-91f4-0f35497a2911 - - - - -] Initialising _HostMountState generation 0 host_up /usr/lib/python3/dist-packages/nova/virt/libvirt/volume/mount.py:133
2019-05-13 13:22:34.733 56943 ERROR oslo_service.service [-] Error starting thread.: nova.exception.InternalError: Nova requires QEMU version 2.8.0 or greater.
2019-05-13 13:22:34.733 56943 ERROR oslo_service.service Traceback (most recent call last):
2019-05-13 13:22:34.733 56943 ERROR oslo_service.service File "/usr/lib/python3/dist-packages/oslo_service/service.py", line 796, in run_service
2019-05-13 13:22:34.733 56943 ERROR oslo_service.service service.start()
2019-05-13 13:22:34.733 56943 ERROR oslo_service.service File "/usr/lib/python3/dist-packages/nova/service.py", line 162, in start
2019-05-13 13:22:34.733 56943 ERROR oslo_service.service self.manager.init_host()
2019-05-13 13:22:34.733 56943 ERROR oslo_service.service File "/usr/lib/python3/dist-packages/nova/compute/manager.py", line 1202, in init_host
2019-05-13 13:22:34.733 56943 ERROR oslo_service.service self.driver.init_host(host=self.host)
2019-05-13 13:22:34.733 56943 ERROR oslo_service.service File "/usr/lib/python3/dist-packages/nova/virt/libvirt/driver.py", line 515, in init_host
2019-05-13 13:22:34.733 56943 ERROR oslo_service.service libvirt_utils.version_to_string(MIN_QEMU_VERSION))
2019-05-13 13:22:34.733 56943 ERROR oslo_service.service nova.exception.InternalError: Nova requires QEMU version 2.8.0 or greater.
2019-05-13 13:22:34.733 56943 ERROR oslo_service.service
this was fixed in ubuntu by the canonical team