Reduces disk space taken by the WSL and Docker vhdx files

CompressWSLdisks.ps1

$ErrorActionPreference = "Stop"

$files = Get-ChildItem -Path C:\Users -Recurse -Include "ext4.vhdx" -Force -ErrorAction SilentlyContinue | Select-Object FullName, Length

wsl -u root fstrim /

foreach ($file in $files) {
	echo "Compacting $file"
	wsl --shutdown
	Mount-VHD -Path $file.FullName -ReadOnly
	Optimize-VHD -Path $file.FullName -Mode Full
	Dismount-VHD $file.FullName
}

Get-ChildItem -Path C:\Users -Recurse -Include "ext4.vhdx" -Force -ErrorAction SilentlyContinue | Select-Object FullName, Length

For some windows editions, you don't have the VHD commandlets, instead you can do:

$ErrorActionPreference = "Stop"

Get-ChildItem -Path C:\Users -Recurse -Include "ext4.vhdx" -Force -ErrorAction SilentlyContinue | Select-Object FullName, Length

wsl -u root fstrim /
wsl --shutdown

diskpart
# Type the rest in the diskpart terminal that just opened
select vdisk file="C:\WSL-Distros\…\ext4.vhdx"
attach vdisk readonly
compact vdisk
detach vdisk
exit

From microsoft/WSL#4699 (comment)

Yeah you can install them manually even on Home editions if you search for smth like "windows home hyperv install".