nova_ssh listens only on migration_interface_address. By default, migration_interface_address == api_interface_address. When migration_interface_address != api_interface_address, resize operations will fail as they utilise my_ip which is still set to api_interface_address and thus nova_compute tries to connect to nova_ssh at api_interface_address which is not listened on by nova_ssh.
An example error is:
Exception during message handling: nova.exception.ResizeError: Resize error: not able to execute ssh command: Unexpected error while running command.
Command: ssh -o BatchMode=yes API_ADDR mkdir -p /var/lib/nova/instances/REDACTED
Exit code: 255
Stdout: ''
Stderr: 'ssh: connect to host API_ADDR port 8022: Connection refused\r\n'
Traceback (most recent call last):
File "/var/lib/kolla/venv/lib/python3.7/site-packages/nova/virt/libvirt/driver.py", line 10385, in migrate_disk_and_power_off
self._remotefs.create_dir(dest, inst_base)
File "/var/lib/kolla/venv/lib/python3.7/site-packages/nova/virt/libvirt/volume/remotefs.py", line 94, in create_dir
on_completion=on_completion)
File "/var/lib/kolla/venv/lib/python3.7/site-packages/nova/virt/libvirt/volume/remotefs.py", line 185, in create_dir
on_execute=on_execute, on_completion=on_completion)
File "/var/lib/kolla/venv/lib/python3.7/site-packages/nova/utils.py", line 105, in ssh_execute
return processutils.execute(*ssh_cmd, **kwargs)
File "/var/lib/kolla/venv/lib/python3.7/site-packages/oslo_concurrency/processutils.py", line 441, in execute
cmd=sanitized_cmd)
The original change, introducing the possibility of this bug, simply switched the addresses: https:/