volumes: - id: "ceph-backend2" type: "partition" min_size: generator: "calc_gb_to_mb" generator_args: [2] label: "Ceph Glance Backend" mount: "none" file_system: "xfs" volumes_roles_mapping: ceph-backend2: - {allocate_size: "min", id: "os"} - {allocate_size: "all", id: "ceph-backend2"}