How to Increase Docker Disk Size in Windows (WSL 2 Backend)

If you are using Docker with WSL 2 backend and cannot increase the disk size from the Docker Desktop settings, follow these steps:

Step 1: Check Current Disk Size

1. Open PowerShell and run:

   wsl --list --verbose

   This will show the installed WSL distributions. Identify the distribution where Docker is installed (usually docker-desktop-data).

2. Shut down WSL:

   wsl --shutdown

Step 2: Locate the WSL Disk Image

The WSL disk image is stored as a .vhdx file. By default, it is located in:

C:\Users\YourUsername\AppData\Local\Docker\wsl\data\ext4.vhdx

(Replace YourUsername with your actual Windows username.)

Step 3: Resize the WSL Disk

1. Open PowerShell as Administrator and run:

   cd "C:\Users\YourUsername\AppData\Local\Docker\wsl\data\"
   wsl --shutdown

2. Run diskpart:

   diskpart

3. Inside diskpart, execute:

   select vdisk file="C:\Users\YourUsername\AppData\Local\Docker\wsl\data\ext4.vhdx"
   expand vdisk maximum=512000
   exit

   (Change 512000 to the required size in MB, e.g., 500GB = 512000MB.)

Step 4: Resize the Filesystem Inside WSL

1. Start WSL again:

   wsl

2. Resize the file system:

   sudo resize2fs /dev/sdX

   (Replace /dev/sdX with the correct partition name, which you can find using df -h inside WSL.)

Step 5: Restart Docker

• Restart Docker Desktop and check if the disk size has increased.

After following these steps, you should be able to allocate more space for Docker volumes.