create cephfs pools

ceph osd pool create data_pool 1024

set up ceph crushmap to have rules selecting hdd only and ssd only

ceph osd getcrushmap -o old_crushmap_compiled
crushtool -d old_crushmap_compiled -o old_crushmap_decompiled

nano old_crushmap_decompiled
## add in the following:
rule ssd_only {
        id 1
        type replicated
        min_size 1
        max_size 10
        step take default class ssd
        step chooseleaf firstn 0 type host
        step emit
}
rule hdd_only {
        id 2
        type replicated
        min_size 1
        max_size 10
        step take default class hdd
        step chooseleaf firstn 0 type host
        step emit
}

crushtool -c old_crushmap_decompiled -o new_crushmap_compiled
ceph osd setcrushmap -i new_crushmap_compiled

ceph osd pool set data_pool crush_rule hdd_only

create ssd cache pool

ceph osd pool create ssd_cache_pool 512
ceph osd pool set ssd_cache_pool crush_rule ssd_only

set up cache tier

ceph osd tier add data_pool ssd_cache_pool
ceph osd tier cache-mode ssd_cache_pool writeback
ceph osd tier set-overlay data_pool ssd_cache_pool

configure ssd cache pool

ceph osd pool set ssd_cache_pool hit_set_type bloom
ceph osd pool set ssd_cache_pool hit_set_count 1
ceph osd pool set ssd_cache_pool hit_set_period 3600   # 1 hour
ceph osd pool set ssd_cache_pool target_max_bytes 1000000000000  # 1 TB
ceph osd pool set ssd_cache_pool min_read_recency_for_promote 1
ceph osd pool set ssd_cache_pool min_write_recency_for_promote 1