When deploying the tripleo_ceph backend for cinder, the cinder.conf setting "report_discard_supported" should be set for RBD backends, to enable use of discard (trim/unmap).
This looks like an easy thing to take care of in puppet-cinder.
Retargeting for OSP-15 as upstream patch is not on stable/rocky, and puppet-cinder community is resistant to backporting patches that are more like a feature than a bug fix.
Verified on: puppet-cinder-14.4.1-0.20190420083336.1cf0604.el8ost.noarch Deployed 15 +ceph below is the ceph conf section from cinder.conf [tripleo_ceph] backend_host=hostgroup volume_backend_name=tripleo_ceph volume_driver=cinder.volume.drivers.rbd.RBDDriver rbd_ceph_conf=/etc/ceph/ceph.conf rbd_user=openstack rbd_pool=volumes rbd_secret_uuid=702c62d2-7a05-11e9-9deb-525400da38c6 report_discard_supported=True -> is enabled OK to verify.
Forgot to set verified, see above.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHEA-2019:2811