The Loopback backend uses node-local storage as storage for datasets. It has no data movement functionality. It serves primarily as a development and testing tool for the other block device backend implementations. You may find it useful if you plan to work on Flocker itself. This backend has no infrastructure requirements: it can run no matter where the Flocker dataset agents run. The configuration item to use Loopback should look like:
"dataset":
"backend": "loopback"
"root_path": "/var/lib/flocker/loopback"
The root_path is a local path on each Flocker dataset agent node where dataset storage will reside.