The Block Storage service enables management of volumes, volume snapshots, and volume types. It includes the following components: cinder-api: Accepts API requests and routes them to cinder-volume for action. cinder-volume: Responds to requests to read from and write to the Block Storage database to maintain state, interacting with other processes (like cinder-scheduler) through a message queue and directly upon block storage providing hardware or software. It can interact with a variety of storage providers through a driver architecture. cinder-scheduler daemon: Like the nova-scheduler, picks the optimal block storage provider node on which to create the volume. Messaging queue: Routes information between the Block Storage service processes. The Block Storage service interacts with Compute to provide volumes for instances.