Volume Driver Standard Capabilities

In the past, there have been attempts to create an interface to abstract the capabilities of different storage solutions that are integrated in Cinder. These capabilities include, but are not limited to QOS, replication factor, bandwidth control, etc. An example with QOS, different backends implement QOS differently:

Vendor A:

        min_iops
        max_iops
        burst_iops

Vendor B:

        Bronze
        Silver
        Gold

Vendor C:

        off
        High priority

Creating an interface with these implementations is not completely possible. After unsuccessful attempts, solutions begin surfacing to just expose a list of capabilities [1][2][3] for the operator to use when creating extra specs.

Capabilities need to be exposed to the cloud administrator from Cinder, so that Cinder is not limiting what storage backends can do. However, the capabilities need to be presented from a common interface when possible, so that the user experience and usefulness of Cinder is not lost.