Hi everyone, In the purpose to deploy a medium size of ceph cluster (300 OSD) we have 6 bare-metal server for the OSD, and 5 bare-metal server for the service (MDS, Mon, etc.) Those 5 bare-metal server have each 48 cores and 256 Gb. What would be the smartest way to use those 5 server, I see two way : first : Server 1 : MDS,MON, grafana, prometheus, webui Server 2: MON Server 3: MON Server 4 : MDS Server 5 : MDS so 3 MDS, 3 MON. and we can loose 2 servers. Second KVM on each server Server 1 : 3 VM : One for grafana & CIe, and 1 MDS, 2 MON other server : 1 MDS, 1 MON in total : 5 MDS, 5 MON and we can loose 4 servers. So on paper it's seem the second are smarter, but it's also more complex, so my question are «is it worth the complexity to have 5 MDS/MON for 300 OSD». Important : The main goal of this ceph cluster are not to get the maximum I/O speed, I would not say the speed is not a factor, but it's not the main point. Regards. -- Albert SHIH 🦫 🐸 Observatoire de Paris France Heure locale/Local time: ven. 17 nov. 2023 10:49:27 CET