Docker users often face challenges related to storage, especially when dealing with large container images and volumes. If you are using Docker Desktop on WSL2 with Windows 10 Home, you might want to change the default location where Docker stores its images for reasons like space constraints or organizational preferences. This guide will walk you through the process of changing the Docker images location within WSL2.

Understanding the default setup

When you install Docker Desktop on Windows 10 Home and configure it with WSL2, Docker uses a default path within the virtual machine provided by WSL2 to store images and containers. By default, this location can be found within your WSL distribution’s file system, which exists on your primary system drive. If your C: drive gets filled up quickly and you need better control over where Docker stores its images, you might want to change this setup.

Steps to change the location of Docker images

1. Install Docker Desktop and WSL2

Ensure that Docker Desktop is installed on your Windows 10 Home machine and that you have the WSL2 feature enabled. Docker Desktop can be downloaded from the official Docker website.

2. Configure Docker Desktop to use WSL2

Upon installation, configure Docker to use the WSL2 engine, which should provide a better performance compared to the legacy Hyper-V solution on systems like Windows 10 Home.

3. Stop Docker Desktop

Before changing the image storage location, it’s necessary to stop Docker Desktop completely. Exiting the application ensures that no background processes are running that could interfere with moving the Docker data directory.

# Stop Docker Desktop from the taskbar or use this command in PowerShell
Stop-Process -Name "Docker Desktop"

4. Locate the current Docker data directory

The data directory typically resides inside the primary WSL distribution. You can access this directory from your WSL2 shell (such as Ubuntu) or using the explorer.exe integration feature in WSL:

# Open WSL2 and navigate to Docker's default data directory
cd /var/lib/docker

5. Copy or sync data to the new location

Choose a new location on another drive, say D:, and create a directory for Docker data.

# Assuming you want to move Docker data to D:\DockerData
# Copy the existing data to this new location
rsync -a /var/lib/docker /mnt/d/DockerData

6. Bind mount the new directory

To ensure Docker uses the new path, you need to create a bind mount. Start by editing the wsl.conf file of your Linux distribution environment:

# Use a text editor to open the wsl.conf file
sudo nano /etc/wsl.conf

Add or modify these lines to your wsl.conf:

1[automount]
2root = /
3options = "metadata"
4mountFsTab = false
5
6[interop]
7enabled=false
8
9[user]
10default=root
11
12[filesystem]
13bind = "$(realpath /mnt/d/DockerData)"

This configuration mount binds your new Docker data directory in place of the default.

7. Restart Docker Desktop

Restart Docker Desktop and verify that it uses the new location for storing images and containers. You can do this by checking Docker settings or by running a container and inspecting the space used in the new directory.

1# Check if Docker works as intended
2docker run hello-world
3
4# Verify the image data directory
5docker info

Additional considerations

• Backup: Always backup your Docker data before making major changes to its configuration.
• Permissions: Ensure the new directory has appropriate permissions so that the WSL2 user can access it without issues.
• Performance: Running Docker on a separate physical drive could improve performance by reducing the I/O contention on your system drive.

Summary Table

By following these steps, you've successfully reconfigured Docker Desktop on Windows 10 Home to store its images and containers in a custom directory. With this approach, you’ll gain better control over your storage and ensure that Docker's presence doesn’t overcrowd your system drive, providing a smoother and more organized development environment.