WSL 2 upgrade on windows

Few days ago I would like to use docker from windows with docker composer. And because I am using ansible, I found easier to deal from Linux so I naturally use WSL.

But when I start to launch docker, a warning message tells me WSL 1 is installed but not WSL 2.

So how to upgrade from WSL 1 to WSL 2.

First, identify versions of WSL by using :

wsl --list

Result tells me that I use Ubuntu-20.04 and WSL 2 but I still get a warning message that Ubuntu not running under WSL 2.

I found this article from Microsoft Docs : Troubleshooting Windows Subsystem for Linux | Microsoft Docs talking about an error : "Invalid command line option: wsl --set-version Ubuntu 2".

So, secondly, I try to update by using this command :

wsl --set-version Ubuntu-20.04 2

And it works. My Ubuntu 20.04 is now working on WSL2.

Hoping it will help others.