Comment 2 for bug 1782714

Note the "Attached to cirros-01 on /dev/vdb Attached to cirros-01 on /dev/vdb" during the live migration. That's probably while the volume has 2 attachments to the same server, one on the source host and one on the destination host. My guess is the attached_mode is lost during the creation/update of the 2nd attachment for the destination host.

Are you able to get the attachment details before and after the live migration and see what those look like using this API?

https://developer.openstack.org/api-ref/block-storage/v3/#list-attachments-with-details

or https://developer.openstack.org/api-ref/block-storage/v3/#list-attachments-with-details

Unfortunately GET /v3/{project_id}/attachments/detail doesn't support filtering by volume_id.