This tool gets the volume container of a given container and writes the volume container's json and all volumes found to a tarball. After that, this tool can be used to restore a volume container from that tarball.
Let say you have a container named mysql-data to keep /var/lib/mysql. You start up your mysql server by running:
$ docker run --volumes-from=mysql-data --name mysql-server ...
Backup that data container:
$ docker-backup store mysql-server-backup.tar mysql-server
Restore it on a new system:
$ docker-backup restore mysql-server-backup.tar
For general documentation on how to use volume containers, see: http://docs.docker.io/en/latest/use/working_with_volumes/#creating-and-mounting-a-data-volume-container
For a more complete backup strategy built on top of docker-backup, look at https://github.com/discordianfish/docker-lloyd.
To run docker-backup itself as a Container, you need to bind-mount the Docker socket, Docker's data directory and point docker-backup via the -addr flag to the location of docker.sock within the container:
$ docker run -v /var/run/docker.sock:/docker.sock \
-v /var/lib/docker/vfs/dir:/var/lib/docker/vfs/dir fish/docker-backup -addr /docker.dock ...