Comment 1 for bug 1845161

Thank you for your bug report and especially for the clear reproduction instructions.

I did not manage to reproduce the problem in my environment. That was a master devstack and I performed a hard reboot of the vm, but the QoS backend settings were not lost after it. On the other hand I had different interface names, likely because we are using different firewall drivers. And that may be the reason we're seeing different behavior. Which firewall_driver is in your neutron config? Mine was 'noop'.