[ceph-users] best practices for cephfs on hard drives mimic

Hi all, In the era of Mimic, what are best practices for setting up cephfs on a hard drive only cluster? Our old cluster which began life in Emperor and has been upgraded until now running Mimic. 21 hard drives ranging from 1 to 4 TB. (Yeah, ceph doesn't like that.) It has a triply replicated cache tier in front of a k2m2 erasure coded pool. Our main usage these days is cephfs. I vaguely remember a few ideas, which might be out of date or never true: Bluestore is slower than filestore on hard drives. ? Before release X replicated caches were needed to interface between writers and the erasure coded pool, but after release X one could write directly to the erasure coded pool. ? Thanks for your input! Chad.