1.3.4. Block Storage - Cinder

The Cinder service provides persistent block storage management for virtual hard drives. The block storage system manages the creation, attaching, and detaching of the block devices to servers. Block storage volumes are fully integrated into Nova and Horizon, which allows cloud users to manage their own storage needs.
Block storage is appropriate for performance-sensitive scenarios such as database storage, expandable file systems, or providing a server with access to raw block-level storage. Additionally, snapshots can be taken to either restore data or to create new block storage volumes (snapshots are dependent upon driver support).
Basic operations include:
  • Create, list, and delete volumes.
  • Create, list, and delete snapshots.
  • Attach and detach volumes to running virtual machines.
Cinder is composed of the following:
  • openstack-cinder-volume, which carves out storage for virtual machines on demand. A number of drivers are provided for interaction with storage providers.
  • openstack-cinder-api, which responds to and handles requests, and places them in the message queue.
  • openstack-cinder-scheduler, which assigns tasks to the queue and determines the provisioning volume server.
  • MySQL database, for state information.