when build armbian via docker "proces will create and run a named Docker container armbian with 2 named volumes armbian-cache and armbian-ccache" and store it in /var. My root amount is not over 40Gb and it will be good thing to store armbian-cache and armbian-ccache in different place

57 minutes ago, Andy Kononov said:

it will be good thing

Agree. https://www.armbian.com/get-involved/ 

You could mount a different volume at the place those directories are.  Might even work with a symlink

 

found solution

First create directory and file for custom configuration:

sudo mkdir -p /etc/systemd/system/docker.service.d sudo $EDITOR /etc/systemd/system/docker.service.d/docker-storage.conf

For docker version before 17.06-ce paste:

[Service] ExecStart= ExecStart=/usr/bin/docker daemon -H fd:// --graph="/mnt"

For docker after 17.06-ce paste:

[Service] ExecStart= ExecStart=/usr/bin/dockerd -H fd:// --data-root="/mnt"

Alternative method through daemon.json

I recently tried above procedure with 17.09-ce on Fedora 25 and it seem to not work. Instead of that simple modification in /etc/docker/daemon.json do the trick:

{ "graph": "/mnt", "storage-driver": "overlay" }

Despite the method you have to reload configuration and restart Docker:

sudo systemctl daemon-reload sudo systemctl restart docker

To confirm that Docker was reconfigured:

docker info|grep "loop file"

In recent version (17.03) different command is required:

docker info|grep "Docker Root Dir"

Output should look like this:

Data loop file: /mnt/devicemapper/devicemapper/data Metadata loop file: /mnt/devicemapper/devicemapper/metadata

Or:

Docker Root Dir: /mnt

Then you can safely remove old Docker storage:

rm -rf /var/lib/docker