Back up Windows WSL distros
The best way to backup your distros is available in Windows Version 1809 and later.
You can export your entire distribution to a tarball using the
wsl --export command.
You can then import this distro back into WSL using the
wsl --import command, allowing you to backup and save states of your WSL distributions.
Please note that traditional backup services that backup files in your Appdata folders (like Windows Backup) will not corrupt your Linux files.