Ceph, being a core component of OCS suite, has the network requirements specifically outlined in the product documentation. The crucial part of these requirements are those regarding the bandwidth concerns: https://access.redhat.com/documentation/en-us/red_hat_ceph_storage/4/html-single/hardware_guide/index#network-considerations_hw ---8<--- 2.5. Network considerations Carefully consider bandwidth requirements for the cluster network, be mindful of network link oversubscription, and segregate the intra-cluster traffic from the client-to-cluster traffic. Important Red Hat recommends using 10 GB Ethernet for Ceph production deployments. 1 GB Ethernet is not suitable for production storage clusters. ... At a minimum, a single 10 GB Ethernet link should be used for storage hardware. If the Ceph nodes have many drives each, add additional 10 GB Ethernet links for connectivity and throughput. --->8--- However there is nothing said about the required bandwidth in ODF documentation: https://access.redhat.com/documentation/en-us/red_hat_openshift_data_foundation/4.12/html-single/planning_your_deployment/index#network-requirements_rhodf The only things mentioned there are the IPv6 addressing and Multus support, which is currently a technology preview feature. I believe that the networking requirements for the OCS deployment should include those for standalone Ceph installation, since a slow network between the worker nodes can become a bottleneck causing the communication failures between the Ceph components, which then leads into: - poor performance of a storage cluster (both on heavy workloads and/or recovery operations) - missed heartbeats from the osd/mon/mgr daemons, resulting into the respective pods crashing or constant monitor re-elections due to quorum changes We have actually observed this behaviour in quite a few customer scenarios, where they were running OCS cluster on less than 10G network, and thus facing the above issues. Based on the above, i suggest that we should probably update the ODF docs to include the network specifications in the same way, as we currently have them in the Ceph documentation. Regards, Sergii