Comment 5 for bug 1897424

Again, this timeout has nothing to do with the time taken to connect volumes. The RPCAPI call that's timing out in your environment is reserve_block_device_name:

https://github.com/openstack/nova/blob/2745e685376abbc4c32516837f6074a3de23aa24/nova/compute/manager.py#L6930-L6969

To understand why that's taking so long we really need to see n-cpu logs covering req-408c9350-fe1e-11ea-b09f-ad32aa0197ce. Your task state change will do nothing to avoid this btw.