In Cinder's G2 release, a new scheduler called filter scheduler has been included. This scheduler decides volume placement based on filtering result with various filters. One of the default filter is 'CapabilitiesFilter' which takes volume type extra specs as capabilities requirement, and would check the capabilities reported by volume backends. This new change impact the volume type test in tempest https://github.com/openstack/tempest/blob/master/tempest/tests/volume/admin/test_volume_types.py
The test is to create a volume type with extra specs and then create/delete volume using this type. It worked well before when simple scheduler was the default, which took no use of volume type and extra spec info. But it would fail when filter scheduler is used. The reason is that no volume driver supports the fake capabilities in the test case. So scheduler fails to find one host to serve that request. It's like creating a Nova flavor stating requires CPU arch to be SPARC while running the test on top X86 servers.
This test has been show stopper for tempest gating job if Cinder uses filter scheduler as default. The fix is simple, use real capabilities instead of fake ones in test.
Fix proposed to branch: master
Review: https:/