Move docker data directory to another location on Ubuntu.md

Move docker data/volumes directory to another location on Ubuntu

The standard data directory used for docker is /var/lib/docker, and since this directory will store all your images, volumes, etc. it can become quite large in a relative small amount of time.

Here's a guide how to change that folder to another location, for example another disk.

1. Stop docker daemon

$ sudo service docker stop

2. Add a configuration file to tell the docker daemon what is the location of the data directory. Create and edit /etc/docker/daemon.json.

$ sudo nano /etc/docker/daemon.json

{ 
   "data-root": "/disk2/docker" 
}

3. Copy the current data directory to the new one.

$ sudo rsync -aP /var/lib/docker/ /disk2/docker

4. Rename the old docker directory

$ sudo mv /var/lib/docker /var/lib/docker.old

5. Restart the docker daemon

$ sudo service docker start

Your containers should now be starting and reading/writing to the new location.

If you feel crazy, delete the old path.

$ sudo rm -rf /var/lib/docker.old