About qcow2:
It seems that nova refuses to convert qcow2 images that have a backing file, at least here: https://opendev.org/openstack/nova/src/commit/c97507dfcd57cce9d76670d3b0d48538900c00e9/nova/virt/images.py#L127
Same for cinder: https://opendev.org/openstack/cinder/src/commit/dcec2f6f01ffc63dc058f641370e9f5a0bad07e4/cinder/image/image_utils.py#L659
I think glance also rejects qcow2 that have backing files: https://opendev.org/openstack/glance/src/branch/master/glance/async_/flows/base_import.py#L178 but I am not sure that's the case everywhere.
About qcow2:
It seems that nova refuses to convert qcow2 images that have a backing file, at least here: /opendev. org/openstack/ nova/src/ commit/ c97507dfcd57cce 9d76670d3b0d485 38900c00e9/ nova/virt/ images. py#L127
https:/
Same for cinder: https:/ /opendev. org/openstack/ cinder/ src/commit/ dcec2f6f01ffc63 dc058f641370e9f 5a0bad07e4/ cinder/ image/image_ utils.py# L659
I think glance also rejects qcow2 that have backing files: /opendev. org/openstack/ glance/ src/branch/ master/ glance/ async_/ flows/base_ import. py#L178
https:/
but I am not sure that's the case everywhere.