4 - must scrub before tier agent can activate
11 - sudo ceph osd pool create base 4
12 - sudo ceph osd pool create cache 4
13 - sudo ceph osd tier add base cache
14 - sudo ceph osd tier cache-mode cache writeback
15 - sudo ceph osd tier set-overlay base cache
16 - sudo ceph osd pool set cache hit_set_type bloom
17 - sudo ceph osd pool set cache hit_set_count 8
18 - sudo ceph osd pool set cache hit_set_period 3600
19 - sudo ceph osd pool set cache target_max_objects 250
20 - sudo ceph osd pool set cache min_read_recency_for_promote 0
21 - sudo ceph osd pool set cache min_write_recency_for_promote 0