The test_incremental_backup test fails in cases where the volume and server are created in different availability zones (AZs). This issue arises because the availability_zone parameter is not explicitly set during volume creation, causing the volume to default to a backend-defined AZ instead of matching the server's AZ.

Captured traceback:
~~~~~~~~~~~~~~~~~~~
Traceback (most recent call last):

File "/usr/lib/python3.9/site-packages/cinder_tempest_plugin/api/volume/test_volume_backup.py", line 117, in test_incremental_backup
server = self.create_server(

File "/usr/lib/python3.9/site-packages/cinder_tempest_plugin/api/volume/base.py", line 148, in create_server
body, _ = compute.create_test_server(

File "/usr/lib/python3.9/site-packages/tempest/common/compute.py", line 359, in create_test_server
LOG.exception('Server %s failed to delete in time',

File "/usr/lib/python3.9/site-packages/oslo_utils/excutils.py", line 227, in _exit_
self.force_reraise()

File "/usr/lib/python3.9/site-packages/oslo_utils/excutils.py", line 200, in force_reraise
raise self.value

File "/usr/lib/python3.9/site-packages/tempest/common/compute.py", line 323, in create_test_server
server = waiters.wait_for_server_status(

File "/usr/lib/python3.9/site-packages/tempest/common/waiters.py", line 80, in wait_for_server_status
raise exceptions.BuildErrorException(details, server_id=server_id)

tempest.exceptions.BuildErrorException: Server 6b1fa8f1-858f-4fa8-9cc7-a12813d38e03 failed to build and is in ERROR status
Details: Fault:

{'code': 500, 'created': '2024-11-26T19:24:12Z', 'message': 'Build of instance 6b1fa8f1-858f-4fa8-9cc7-a12813d38e03 aborted: Invalid volume: Instance 6b1fa8f1-858f-4fa8-9cc7-a12813d38e03 and volume a8a200f3-e121-40fc-8854-ec820ded325b are not in the same availability_zone. Instance is in az1. Volume is in az0'}

. Request ID of server operation performed before checking the server status req-c9533790-9d97-4c22-92bd-6d5b24d05312.