Due to the ability to design and build cost-effective OSD nodes, Ceph enables you to build large high-performance storage clusters that are very cost-effective compared with alternative options. However, due to the recommended 3x replication, storage efficiency as calculated against raw storage cannot match traditional RAID JBOD (short for Just a Bunch of Disks) on price or power consumption. However, a lot of the benefits surrounding availability and performance may still make this use case attractive. Erasure coding support for use with RBD's, which should be available by the Luminous release, will close this gap greatly. If your archival requirement allows you to store data in objects, then erasure pools will enable you to match RAID on price and is a very attractive solution.