Minimum for Ceph is 3 nodes but not recomended for production.
You should use at least 6 nodes, 2 osd each and an enteprise ssd for bluestore db. Hardware, CPU 1 core for each OSD, 1GB RAM for each 1TB of OSD, 3 gigabit network cards, one for proxmox network, two for ceph network (bond).
Do...