[ceph-users] cephfs file layouts, empty objects in first data pool

Hi, running 14.2.6, debian buster (backports). Have set up a cephfs with 3 data pools and one metadata pool: myfs_data, myfs_data_hdd, myfs_data_ssd, and myfs_metadata. The data of all files are with the use of ceph.dir.layout.pool either stored in the pools myfs_data_hdd or myfs_data_ssd. This has also been checked by dumping the ceph.file.layout.pool attributes of all files. The filesystem has 1617949 files and 36042 directories. There are however approximately as many objects in the first pool created for the cephfs, myfs_data, as there are files. They also becomes more or fewer as files are created or deleted (so cannot be some leftover from earlier exercises). Note how the USED size is reported as 0 bytes, correctly reflecting that no file data is stored in them. POOL_NAME USED OBJECTS CLONES COPIES MISSING_ON_PRIMARY UNFOUND DEGRADED RD_OPS RD WR_OPS WR USED COMPR UNDER COMPR myfs_data 0 B 1618229 0 4854687 0 0 0 2263590 129 GiB 23312479 124 GiB 0 B 0 B myfs_data_hdd 831 GiB 136309 0 408927 0 0 0 106046 200 GiB 269084 277 GiB 0 B 0 B myfs_data_ssd 43 GiB 1552412 0 4657236 0 0 0 181468 2.3 GiB 4661935 12 GiB 0 B 0 B myfs_metadata 1.2 GiB 36096 0 108288 0 0 0 4828623 82 GiB 1355102 143 GiB 0 B 0 B Is this expected? I was assuming that in this scenario, all objects, both their data and any keys would be either in the metadata pool, or the two pools where the objects are stored. Is it some additional metadata keys that are stored in the first created data pool for cephfs? This would not be so nice in case the osd selection rules for it are using worse disks than the data itself... Btw: is there any tool to see the amount of key value data size associated with a pool? 'ceph osd df' gives omap and meta for osds, but not broken down per pool. Best regards, Håkan