[ceph-users] cache tiering or bluestore partitions

We are planning our ceph architecture and I have a question: How should NVMe drives be used when our spinning storage devices use bluestore: 1. block WAL and DB partitions (https://docs.ceph.com/docs/nautilus/rados/configuration/bluestore-config-re…) 2. Cache tier (https://docs.ceph.com/docs/nautilus/rados/operations/cache-tiering/) 3. Something else? Hardware- Each node has: 3x 8 TB HDD 1x 450 GB NVMe drive 192 GB RAM 2x Xeon CPUs (24 cores total) I plan to have three OSD daemons running on the node. There are 95 nodes total with the same hardware. Use Case: The plan is create cephfs and use this filesystem to store people's home directories and data. I anticipate more read operations than writes. Regarding cache tiering: The online documentation says cache tiering will often degrade performance. But when I read various threads on this ML there do seem to be people using cache tiering with success. I do see that it is heavily dependent upon one's use-case. In 2019 is there any updated recommendations as to whether to use cache tiering? If there is a third suggestion that people have I would be interested in hearing it. Thanks in advance. Sincerely, Shawn Kwang