Thank you for your response. Sadly, I'm talking about actual production, but I'm very limited in terms of hardware. I was thinking about using RAID for controller node as data redundancy, because I had the idea of maximizing the number of nova compute nodes, So basically i thought off using a controller with the following services ( Nova, Neutron, Keystone, Horizon, Glance, Cinder and Swift). Following the configuration you suggested, I would have : - 3 Controllers that are also Ceph Monitors - 9 Nova compute nodes and Ceph OSDs My questions are : - having multiple Ceph monitors is for the sake of redundancy or does it have a performance goal ? - Combining Ceph OSD and Nova compute wouldn't have performance drawbacks or damage the integrity of data stored in each node. wouldn't it be better is this case to use two separate servers for swift and glance and use RAID for data redundancy instead of using Ceph SDS. Thank you very much for you time.