I agree with zhangjl, It seems that there is something wrong with your ssh keys, as you can see from the logs:
Command: ssh 10.35.104.17 mkdir -p /var/lib/nova/instances/3b7ef5ae-94f4-44a8-a028-104e35cc9505 Exit code: 255 Stdout: '' Stderr: 'Host key verification failed.\r\n'
Also, with this bug resolved https://bugs.launchpad.net/nova/+bug/1233184, the migrating instance will not be set to an ERROR state, on failed migration.
I agree with zhangjl, It seems that there is something wrong with your ssh keys, as you can see from the logs:
Command: ssh 10.35.104.17 mkdir -p /var/lib/ nova/instances/ 3b7ef5ae- 94f4-44a8- a028-104e35cc95 05
Exit code: 255
Stdout: ''
Stderr: 'Host key verification failed.\r\n'
Also, with this bug resolved https:/ /bugs.launchpad .net/nova/ +bug/1233184, the migrating instance will not be set to an ERROR state, on failed migration.