Ceph » bluestore

The documentation in at least one place:
https://docs.ceph.com/en/pacific/man/8/ceph-bluestore-tool/ bluefs-bdev-migrate says that:
if source list has slow volume only - operation isn’t permitted, requires explicit allocation via new-db/new-wal command.

The rook documentation makes a similar claim about hardware types cant be the same.

I spent a couple days trying to figure out how to work around it but when I tried just doing it, it worked. So maybe the documentation is wrong, or is confusing enough I misinterpreted it.

With rook, this works:
- name: "minikube-m03"
devices:
- name: "vdb"
config:
metadataDevice: db/db1
- name: "vdc"
config:
metadataDevice: db/db2

where vdb & db/db1 are both on hdds. also tried it with ssd/ssd and it works ok there too.