OpenStack Block Storage differs from traditional block storage

Traditional storage has always been designed with integrated stack or unitary delivery mechanisms in mind. When you talk about traditional storage systems from NetApp, EMC or any of these players, everything you need to deliver persistent storage to the compute layer is within the stack or the platform that is provided by the vendor. You don't need to go outside of that vendor's platform to deliver any kind of storage services. Whether it is persistent storage in the form of disks, data resiliency in the form of RAID, data management, snapshots, clones and/or any data mobility functions, any and all functions that you need to get the most out of your storage platform are delivered from within the storage system itself.