How can I change the location of docker images when using Docker Desktop on WSL2 with Windows 10 Home?

Question

I've just upgraded to Windows 10 Home May 2020, activated WSL2, and installed Docker Desktop.

WSL2 must be installed in my system disk, which is a small SSD. I don't want to fill it with docker images. How do I change the docker images path? I'd like to use a path in my big Windows filesystem.

The image location is somewhat confusing. I believe it is in /mnt/wsl/docker-desktop-data/.

How do I change the directory of docker images inside WSL2? May I change docker configuration to select a path inside /mnt/d, or mount a path from /mnt/d over docker data dirs?

Answer 1

The WSL 2 docker-desktop-data vm disk image would normally reside in: %USERPROFILE%\AppData\Local\Docker\wsl\data\ext4.vhdx

Follow the following to relocate it to other drive/directory, with all existing docker data preserved (tested against Docker Desktop 2.3.0.4 (46911), and continued to work after updating the 3.1.0 (51484)):

First, shut down your docker desktop by right click on the Docker Desktop icon and select Quit Docker Desktop

Then, open your command prompt:

wsl --list -v

You should be able to see, make sure the STATE for both is Stopped.

  NAME                   STATE           VERSION
* docker-desktop         Stopped         2
  docker-desktop-data    Stopped         2

Export docker-desktop-data into a file

wsl --export docker-desktop-data "D:\Docker\wsl\data\docker-desktop-data.tar"

Unregister docker-desktop-data from wsl, note that after this, your ext4.vhdx file would automatically be removed (so back it up first if you have important existing image/container):

wsl --unregister docker-desktop-data

Import the docker-desktop-data back to wsl, but now the ext4.vhdx would reside in different drive/directory:

wsl --import docker-desktop-data "D:\Docker\wsl\data" "D:\Docker\wsl\data\docker-desktop-data.tar" --version 2

Start the Docker Desktop again and it should work

You may delete the D:\Docker\wsl\data\docker-desktop-data.tar file (NOT the ext4.vhdx file) if everything looks good for you after verifying