Introduction
When a basic compute instance is launched, where the instance data resides on the compute host's disks for the duration of the running instance, the data written to it is not persistent after termination—meaning that any data saved on the disk will be lost when a user requests to destroy that instance. There is a solution for this in OpenStack. Volumes are persistent storage that you can attach to your running OpenStack Compute instances; the best analogy is that of a USB drive that you can attach to an instance. Like USB drives, you can only attach instances to one computer at a time.
Note
There is currently an experimental feature that allows you to attach a volume to multiple instances. We do not cover it here nor recommend its usage at this time.
The OpenStack Block Storage project code name Cinder provides the interfaces and automation that allows the connection of storage volumes to OpenStack Compute instances. OpenStack Block Storage is very similar to Amazon Elastic Block...