Comment 9 for bug 1636561

And there is root cause:
our test scenario works like this:

1. Get a controller
2. Call 'killall -s TERM corosync' on it
3. Get controller fqdn
4. Go to other controller
5. Call 'pcs status' on it
6. Get offline nodes from output
7. Check that our first controller is in 'Offline' nodes from output
8. If last is not True, throw an exception about splitbrain

But problem is that between calling 'killall' on the first controller and 'pcs status' on the second, corosync got cluster synced back and on second node we have all the nodes online in one cluster. And it is awesome, actually.
So, we should fix the test itself, I believe. My proposal is to change the check to [0] that all nodes is or online and in one cluster or first controller is offline.

[0] https://github.com/openstack/fuel-qa/blob/master/fuelweb_test/tests/tests_strength/test_failover_base.py#L1139-L1140