@Bence: thanks for the report. Could you attach the nova-compute debug log from devstack0a (the target host of the evacuation) that contains at least the time frame of the two evac request arriving and then the second one failing? This would help a lot seeing what steps are overlapping.
@Bence: thanks for the report. Could you attach the nova-compute debug log from devstack0a (the target host of the evacuation) that contains at least the time frame of the two evac request arriving and then the second one failing? This would help a lot seeing what steps are overlapping.