Comment 2 for bug 1839181

Some characters of this issue:
- It is seen 5/5 times since 20190728T233000Z load.
- The host got lock/unlocked was compute-0, but the alarm was against compute-1
- The alarm seems to a stale alarm, there was no vm hosted on compute-1 and the alarm stays uncleared
- The alarm on compute-1 eventually got cleared after another lock/unlock of compute-0

Title is updated based on above observations.