Traceback as seen in nova compute logs

2021-02-11 18:46:16.194 898529 ERROR nova.compute.manager [instance: e3967a91-3f5d-45b3-9300-28f8ee936fa3] Traceback (most recent call last):
2021-02-11 18:46:16.194 898529 ERROR nova.compute.manager [instance: e3967a91-3f5d-45b3-9300-28f8ee936fa3] File "/usr/lib/python3/dist-packages/nova/compute/manager.py", line 6722, in _do_live_migration
2021-02-11 18:46:16.194 898529 ERROR nova.compute.manager [instance: e3967a91-3f5d-45b3-9300-28f8ee936fa3] block_migration, disk, dest, migrate_data)
2021-02-11 18:46:16.194 898529 ERROR nova.compute.manager [instance: e3967a91-3f5d-45b3-9300-28f8ee936fa3] File "/usr/lib/python3/dist-packages/nova/compute/rpcapi.py", line 770, in pre_live_migration
2021-02-11 18:46:16.194 898529 ERROR nova.compute.manager [instance: e3967a91-3f5d-45b3-9300-28f8ee936fa3] disk=disk, migrate_data=migrate_data)
2021-02-11 18:46:16.194 898529 ERROR nova.compute.manager [instance: e3967a91-3f5d-45b3-9300-28f8ee936fa3] File "/usr/lib/python3/dist-packages/oslo_messaging/rpc/client.py", line 178, in call
2021-02-11 18:46:16.194 898529 ERROR nova.compute.manager [instance: e3967a91-3f5d-45b3-9300-28f8ee936fa3] retry=self.retry)
2021-02-11 18:46:16.194 898529 ERROR nova.compute.manager [instance: e3967a91-3f5d-45b3-9300-28f8ee936fa3] File "/usr/lib/python3/dist-packages/oslo_messaging/transport.py", line 128, in _send
2021-02-11 18:46:16.194 898529 ERROR nova.compute.manager [instance: e3967a91-3f5d-45b3-9300-28f8ee936fa3] retry=retry)
2021-02-11 18:46:16.194 898529 ERROR nova.compute.manager [instance: e3967a91-3f5d-45b3-9300-28f8ee936fa3] File "/usr/lib/python3/dist-packages/oslo_messaging/_drivers/amqpdriver.py", line 645, in send
2021-02-11 18:46:16.194 898529 ERROR nova.compute.manager [instance: e3967a91-3f5d-45b3-9300-28f8ee936fa3] call_monitor_timeout, retry=retry)
2021-02-11 18:46:16.194 898529 ERROR nova.compute.manager [instance: e3967a91-3f5d-45b3-9300-28f8ee936fa3] File "/usr/lib/python3/dist-packages/oslo_messaging/_drivers/amqpdriver.py", line 636, in _send
2021-02-11 18:46:16.194 898529 ERROR nova.compute.manager [instance: e3967a91-3f5d-45b3-9300-28f8ee936fa3] raise result
2021-02-11 18:46:16.194 898529 ERROR nova.compute.manager [instance: e3967a91-3f5d-45b3-9300-28f8ee936fa3] oslo_messaging.rpc.client.RemoteError: Remote error: ProcessExecutionError Unexpected error while running command.
2021-02-11 18:46:16.194 898529 ERROR nova.compute.manager [instance: e3967a91-3f5d-45b3-9300-28f8ee936fa3] Command: scp -r host:/var/lib/nova/instances/e3967a91-3f5d-45b3-9300-28f8ee936fa3/disk.config /var/lib/nova/instances/e3967a91-3f5d-45b3-9300-28f8ee936fa3
2021-02-11 18:46:16.194 898529 ERROR nova.compute.manager [instance: e3967a91-3f5d-45b3-9300-28f8ee936fa3] Exit code: 1
2021-02-11 18:46:16.194 898529 ERROR nova.compute.manager [instance: e3967a91-3f5d-45b3-9300-28f8ee936fa3] Stdout: ''
2021-02-11 18:46:16.194 898529 ERROR nova.compute.manager [instance: e3967a91-3f5d-45b3-9300-28f8ee936fa3] Stderr: 'Host key verification failed.\r\n'
2021-02-11 18:46:16.194 898529 ERROR nova.compute.manager [instance: e3967a91-3f5d-45b3-9300-28f8ee936fa3] ['Traceback (most recent call last):\n', ' File "/usr/lib/python3/dist-packages/oslo_messaging/rpc/server.py", line 166, in _process_incoming\n res = self.dispatcher.dispatch(message)\n', ' File "/usr/lib/python3/dist-packages/oslo_messaging/rpc/dispatcher.py", line 265, in dispatch\n return self._do_dispatch(endpoint, method, ctxt, args)\n', ' File "/usr/lib/python3/dist-packages/oslo_messaging/rpc/dispatcher.py", line 194, in _do_dispatch\n result = func(ctxt, **new_args)\n', ' File "/usr/lib/python3/dist-packages/nova/exception_wrapper.py", line 79, in wrapped\n function_name, call_dict, binary, tb)\n', ' File "/usr/lib/python3/dist-packages/oslo_utils/excutils.py", line 220, in __exit__\n self.force_reraise()\n', ' File "/usr/lib/python3/dist-packages/oslo_utils/excutils.py", line 196, in force_reraise\n six.reraise(self.type_, self.value, self.tb)\n', ' File "/usr/lib/python3/dist-packages/six.py", line 693, in reraise\n raise value\n', ' File "/usr/lib/python3/dist-packages/nova/exception_wrapper.py", line 69, in wrapped\n return f(self, context, *args, **kw)\n', ' File "/usr/lib/python3/dist-packages/nova/compute/utils.py", line 1346, in decorated_function\n return function(self, context, *args, **kwargs)\n', ' File "/usr/lib/python3/dist-packages/nova/compute/manager.py", line 215, in decorated_function\n kwargs[\'instance\'], e, sys.exc_info())\n', ' File "/usr/lib/python3/dist-packages/oslo_utils/excutils.py", line 220, in __exit__\n self.force_reraise()\n', ' File "/usr/lib/python3/dist-packages/oslo_utils/excutils.py", line 196, in force_reraise\n six.reraise(self.type_, self.value, self.tb)\n', ' File "/usr/lib/python3/dist-packages/six.py", line 693, in reraise\n raise value\n', ' File "/usr/lib/python3/dist-packages/nova/compute/manager.py", line 203, in decorated_function\n return function(self, context, *args, **kwargs)\n', ' File "/usr/lib/python3/dist-packages/nova/compute/manager.py", line 6659, in pre_live_migration\n bdm.save()\n', ' File "/usr/lib/python3/dist-packages/oslo_utils/excutils.py", line 220, in __exit__\n self.force_reraise()\n', ' File "/usr/lib/python3/dist-packages/oslo_utils/excutils.py", line 196, in force_reraise\n six.reraise(self.type_, self.value, self.tb)\n', ' File "/usr/lib/python3/dist-packages/six.py", line 693, in reraise\n raise value\n', ' File "/usr/lib/python3/dist-packages/nova/compute/manager.py", line 6624, in pre_live_migration\n migrate_data)\n', ' File "/usr/lib/python3/dist-packages/nova/virt/libvirt/driver.py", line 8343, in pre_live_migration\n self._remotefs.copy_file(src, instance_dir)\n', ' File "/usr/lib/python3/dist-packages/nova/virt/libvirt/volume/remotefs.py", line 108, in copy_file\n compression=compression)\n', ' File "/usr/lib/python3/dist-packages/nova/virt/libvirt/volume/remotefs.py", line 195, in copy_file\n on_completion=on_completion)\n', ' File "/usr/lib/python3/dist-packages/oslo_concurrency/processutils.py", line 424, in execute\n cmd=sanitized_cmd)\n', "oslo_concurrency.processutils.ProcessExecutionError: Unexpected error while running command.\nCommand: scp -r host:/var/lib/nova/instances/e3967a91-3f5d-45b3-9300-28f8ee936fa3/disk.config /var/lib/nova/instances/e3967a91-3f5d-45b3-9300-28f8ee936fa3\nExit code: 1\nStdout: ''\nStderr: 'Host key verification failed.\\r\\n'\n"].
2021-02-11 18:46:16.194 898529 ERROR nova.compute.manager [instance: e3967a91-3f5d-45b3-9300-28f8ee936fa3]