Docker's default directory is /var/lib/docker
Some linux admin likes to assign only a few GBs to the var directory, so running a few docker images can fill up the space very easily.
Here is how to move the default directory to a new directory, usually with a bigger space.
Go to /etc/docker/daemon.json (if it doesn’t exist, create it)
Add the following
{
"data-root": "/new directory/docker"
}
Stop the docker systemd service
$sudo systemctl stop docker
Copy existing docker data from default directory to the new directory
$sudo rsync -axPS /var/lib/docker /new directory/docker
The rsync command might not be available then just yum install it. The used parameters are:
-a, --archive archive mode;
-x, --one-file-system don't cross filesystem boundaries
-P show progress
-S, --sparse handle sparse files efficiently
Note, the rsync doesn't seem to work??? Docker doesn't seem to pick up the old images and containers.
So, make a backup of images to run them using the new directory
Now start docker again
$sudo systemctl start docker
Check if the docker root directory has been changed.
$docker info
Should have:
Docker Root Dir: /new directory/docker
Then load the backup images and run them, if all good, delete old directory
$sudo rm -r /var/lib/docker