Hi everyone, I'm using a Ceph Erasure Coded pool as the backend for OpenStack Cinder. I've created a replicated pool (volumes_meta) for metadata and an erasure-coded pool (volumes_data) for data, following the documentation here: https://docs.ceph.com/en/latest/rados/operations/erasure-code/ When I set rbd_pool to volumes_meta in cinder.conf, I receive an "Insufficient free virtual space" error, even though volumes_data has ample free space. This is because Cinder is calculating free space based on the metadata pool. When rbd_pool is set to volumes_data, Cinder correctly calculates free space based on the data pool. However, I then encounter an "RBD operation not supported" error during volume creation. I need Cinder to recognize the free space available in volumes_data while avoiding the "RBD operation not supported" error. I'm unsure how to configure this correctly and would appreciate any advice. The following is supplemental information. cinder.conf is: [ceph] volume_driver = cinder.volume.drivers.rbd.RBDDriver volume_backend_name = ceph rbd_pool = volumes_meta rbd_ceph_conf = /etc/ceph/ceph.conf rbd_flatten_volume_from_snapshot = false rbd_max_clone_depth = 5 rbd_store_chunk_size = 4 rados_connect_timeout = -1 rbd_user = cinder rbd_secret_uuid = <uuid> For example, if the pool usage is as follows, Cinder gets 1.6TiB as the pool free space: $ ceph df --- POOLS --- POOL ID PGS STORED OBJECTS USED %USED MAX AVAIL volumes_meta 4 32 40 KiB 24 189 KiB 0 1.6 TiB volumes_data 7 32 61 GiB 15.67k 92 GiB 2.80 2.1 TiB $ cinder get-pools --detail +-----------------------------+-----------------------------------------------------------------------------------+ | Property | Value | +-----------------------------+-----------------------------------------------------------------------------------+ | allocated_capacity_gb | 523 | | backend_state | up | | driver_version | 1.3.0 | | filter_function | None | | free_capacity_gb | 1592.07 <-★free capacity of volumes_meta | | goodness_function | None | | location_info | ceph:/etc/ceph/ceph.conf:<uuid>:cinder:volumes_meta | | max_over_subscription_ratio | 20.0 | | multiattach | True | | name | <hostname>@ceph#ceph | | qos_support | True | | replication_enabled | False | | reserved_percentage | 0 | | storage_protocol | ceph | | thin_provisioning_support | True | | timestamp | 2025-05-29T07:44:17.903149 | | total_capacity_gb | 1592.07 | | vendor_name | Open Source | | volume_backend_name | ceph | +-----------------------------+-----------------------------------------------------------------------------------+ OpenStack and Ceph versions are: $ ceph -v ceph version 17.2.8 (f817ceb7f187defb1d021d6328fa833eb8e943b3) quincy (stable) $ dnf list --installed | grep openstack-cinder openstack-cinder.noarch 1:21.3.2-1.el9s @centos-openstack-zed