Hello, The feature BP at https://blueprints.launchpad.net/cinder/+spec/read-only-volumes. The Cinder server side change (https://review.openstack.org/#/c/38322/) was done and merged, but since there was a delay of a few weeks on the Cinder side while team debated between some design options, and I couldn't submit Nova side patchs until the corresponding Cinder patch was merged. So the follow Nova side changes need to request FFE, I need those changes to make the feature workable fully: https://review.openstack.org/#/c/44455/ https://review.openstack.org/#/c/44817/ (depends on cinderclient change https://review.openstack.org/#/c/44672/ ) https://review.openstack.org/#/c/45171/ thanks, zhiyan