Instance resize fails because ssh is not setup between compute nodes

Issue

• vm resize fails
• resizing instance fails

2017-05-05 14:30:06.472 625824 ERROR oslo_messaging.rpc.server ResizeError: Resize error: not able to execute ssh command: Unexpected error while running command.
2017-05-05 14:30:06.472 625824 ERROR oslo_messaging.rpc.server Command: ssh -o BatchMode=yes 192.168.100.111 mkdir -p /var/lib/nova/instances/f96f7544-2aa4-43f6-b0e4-c0bf81a0c6f8
2017-05-05 14:30:06.472 625824 ERROR oslo_messaging.rpc.server Exit code: 255
2017-05-05 14:30:06.472 625824 ERROR oslo_messaging.rpc.server Stdout: u''
2017-05-05 14:30:06.472 625824 ERROR oslo_messaging.rpc.server Stderr: u'Host key verification failed.\r\n'
2017-05-05 14:30:06.472 625824 ERROR oslo_messaging.rpc.server