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copied!<h2>Docker 1.9.0 and above</h2> <p>Use <a href="https://docs.docker.com/engine/reference/commandline/volume_create/" rel="nofollow noreferrer">volume API</a></p> <pre><code>docker volume create --name hello docker run -d -v hello:/container/path/for/volume container_image my_command </code></pre> <p>This means that the data-only container pattern must be abandoned in favour of the new volumes.</p> <p>Actually the volume API is only a better way to achieve what was the data-container pattern.</p> <p>If you create a container with a <code>-v volume_name:/container/fs/path</code> Docker will automatically create a named volume for you that can:</p> <ol> <li>Be listed through the <code>docker volume ls</code></li> <li>Be identified through the <code>docker volume inspect volume_name</code></li> <li>Backed up as a normal directory</li> <li>Backed up as before through a <code>--volumes-from</code> connection</li> </ol> <p>The new volume API adds a useful command that lets you identify dangling volumes:</p> <pre><code>docker volume ls -f dangling=true </code></pre> <p>And then remove it through its name:</p> <pre><code>docker volume rm <volume name> </code></pre> <p>As @mpugach underlines in the comments, you can get rid of all the dangling volumes with a nice one-liner:</p> <pre><code>docker volume rm $(docker volume ls -f dangling=true -q) # Or using 1.13.x docker volume prune </code></pre> <h2>Docker 1.8.x and below</h2> <p>The approach that seems to work best for production is to use a <strong>data only container</strong>.</p> <p>The data only container is run on a barebones image and actually does nothing except exposing a data volume.</p> <p>Then you can run any other container to have access to the data container volumes:</p> <pre><code>docker run --volumes-from data-container some-other-container command-to-execute </code></pre> <ul> <li><a href="http://www.offermann.us/2013/12/tiny-docker-pieces-loosely-joined.html" rel="nofollow noreferrer">Here</a> you can get a good picture of how to arrange the different containers.</li> <li><a href="http://crosbymichael.com/advanced-docker-volumes.html" rel="nofollow noreferrer">Here</a> there is a good insight on how volumes work.</li> </ul> <p>In <a href="http://container42.com/2013/12/16/persistent-volumes-with-docker-container-as-volume-pattern/" rel="nofollow noreferrer">this blog post</a> there is a good description of the so-called <strong>container as volume pattern</strong> which clarifies the main point of having <strong>data only containers</strong>.</p> <p><a href="https://docs.docker.com/engine/userguide/dockervolumes/" rel="nofollow noreferrer">Docker documentation has now the DEFINITIVE description of the <strong>container as volume/s</strong> pattern.</a></p> <p>Following is the backup/restore procedure for Docker 1.8.x and below.</p> <p><strong>BACKUP:</strong></p> <pre><code>sudo docker run --rm --volumes-from DATA -v $(pwd):/backup busybox tar cvf /backup/backup.tar /data </code></pre> <ul> <li>--rm: remove the container when it exits</li> <li>--volumes-from DATA: attach to the volumes shared by the DATA container</li> <li>-v $(pwd):/backup: bind mount the current directory into the container; to write the tar file to</li> <li>busybox: a small simpler image - good for quick maintenance</li> <li>tar cvf /backup/backup.tar /data: creates an uncompressed tar file of all the files in the /data directory</li> </ul> <p><strong>RESTORE:</strong></p> <pre><code># Create a new data container $ sudo docker run -v /data -name DATA2 busybox true # untar the backup files into the new container᾿s data volume $ sudo docker run --rm --volumes-from DATA2 -v $(pwd):/backup busybox tar xvf /backup/backup.tar data/ data/sven.txt # Compare to the original container $ sudo docker run --rm --volumes-from DATA -v `pwd`:/backup busybox ls /data sven.txt </code></pre> <p>Here is a nice <a href="http://container42.com/2014/11/18/data-only-container-madness/" rel="nofollow noreferrer">article from the excellent Brian Goff</a> explaining why it is good to use the same image for a container and a data container.</p>

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