Script to help compact WSL and vhdx.

CompactWSL.bat

@echo off

net session >nul 2>&1
if %errorlevel% neq 0 (
    echo Requesting administrative privileges...
    powershell -Command "Start-Process '%~f0' -Verb RunAs"
    exit /b
)

wsl sudo fstrim --all; echo "Exit status: $?";
wsl --shutdown

:: ========= Instructions =========
:: Please define your list of files here.
set fileList=("%LOCALAPPDATA%\Packages\CanonicalGroupLimited.Ubuntu_79rhkp1fndgsc\LocalState\ext4.vhdx" "%LOCALAPPDATA%\Docker\wsl\data\ext4.vhdx")

:: Process each file in the list.
for %%F in %fileList% do (
    echo Processing %%F using diskpart compact.
    (
        echo select vdisk file=%%F
        echo detach vdisk
        echo attach vdisk readonly
        echo compact vdisk
        echo detach vdisk
    ) | diskpart
)

echo Finished.
pause