Ceph Block Device (RADOS Block Device)
Many deployments using platforms such as OpenStack or DigitalOcean manage and attach RBD images at the virtualization layer, so they appear to the guest operating system through SCSI or Virtio drivers. Here we'll also explore the use of the Linux kernel driver on arbitrary, even bare metal, systems.
The RADOS Block Device (RBD)—formerly known as the Ceph Block Device—provides block-based persistent storage to Ceph clients. The block device is presented as a traditional drive on the client machine. Such a drive can be used in various ways. It can be used as a raw block device or as a filesystem by partitioning, formatting, and subsequently mounting it.
RBD makes use of the librbd
library and stores blocks of data striped over multiple OSDs in a Ceph cluster. RBD is built on the fundamental RADOS layer of Ceph. Thus every block device is spread over multiple Ceph nodes and delivers high performance and excellent reliability.
RBD is rich with enterprise-class...