I have a small cluster with a single crash map. I use 3 pools one (Openebula VMs on rbd), cephfs_data and cephfs_metadata for cephfs. Here is my ceph df RAW STORAGE: CLASS SIZE AVAIL USED RAW USED %RAW USED ssd 94 TiB 78 TiB 17 TiB 17 TiB 17.75 TOTAL 94 TiB 78 TiB 17 TiB 17 TiB 17.75 POOLS: POOL ID STORED OBJECTS USED %USED MAX AVAIL cephfs_data 1 3.3 TiB 6.62M 10 TiB 12.36 24 TiB cephfs_metadata 2 2.1 GiB 447.63k 2.5 GiB 0 24 TiB one 5 2.2 TiB 598.12k 6.6 TiB 8.42 24 TiB What confuses me is an even distribution of MAX_AVAIL storage between those pools. When I mount cephfs on a client host, df -h shows me pool utilization. 28T 3.4T 24T 13% I also have an old hammer cluster where I see a similar picture for ceph df for a one crash map (covering rbd, cephfs-data, cephfs-metadata) GLOBAL: SIZE AVAIL RAW USED %RAW USED 87053G 31306G 55747G 64.04 POOLS: NAME ID USED %USED MAX AVAIL OBJECTS rbd 0 12907G 69.37 5700G 3312474 cephfs-data 12 2873G 33.52 5700G 5859947 cephfs-meta 13 90035k 0 5700G 443961 cloud12g 14 2857G 43.41 3726G 623737 However, df -h on clients show total cluster utilization 86T 55T 31T 65% It seems that the hammer dynamically changes allocation data between the pools on the same crush map as needed. Does nautilus do the same? In this case, does 24 TB means actually avaialble space divided 3 (all my pools are set with 3/2 replication)? Thank you and sorry for the confusion