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.
Deployed 15 +ceph below is the ceph conf section from cinder.conf
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.