Can Windows 10 have WSL1 & WSL2?

Question

Running Windows 10 (ver 21H1 19043.1415).

I enabled the required Windows WSL features some time ago. Since then, I've switched back and forth between WSL1 and WSL2 several times with Linux packages.

I've used Docker for some time. It seems Docker's recent updates transitioned Docker from WSL1 to WSL2 on Windows.

Ubuntu was just uninstalled from the PC. The status of WSL was checked:

wsl --list --verbose

The returned status shows:

NAME	STATE	VERSION
docker-desktop-data	Stopped	2
docker-desktop	Stopped	2

Question: Can the Windows subsystem version of Linux, Ubuntu 20.04, be installed as WSL1? Which means the PC has both WSL1 and WSL2 active?

Answer 1

Yes. Windows 10 can have both WSL1 and WSL2 active.

After exploring the Basic Commands for WSL at Microsoft I learned the Windows sub-system version of Linux can be easily converted from WSL1 to WSL2 or Vice versa.

https://docs.microsoft.com/en-us/windows/wsl/basic-commands

Below demonstrates how Ubuntu (or other distros) can be converted from WSL1-WSL2 and back and forth. All commands were commands given in the Windows Terminal (the new PowerShell). The PowerShell command(s) to convert are:

wsl --set-version ubuntu 1
wsl --set-version ubuntu 2

Ubuntu was (just) reinstalled (again) from the Microsoft Store. The User name and Password were created. No sudo update/upgrades were done (yet). The WSL status was checked and showed the newly installed (running) Ubuntu was installed as WSL2.

PS C:\Users\prior> wsl --list --verbose

NAME	STATE	VERSION
docker-desktop-data	Stopped	2
docker-desktop	Stopped	2
Ubuntu	Running	2

Then Ubuntu was converted from WSL2 to WSL1. The status was checked again. This showed Ubuntu converted to WSL1 and stopped.

  PS C:\Users\prior> wsl --set-version ubuntu 1

Conversion in progress, this may take a few minutes... Conversion complete.

  PS C:\Users\prior> wsl --list --verbose

NAME	STATE	VERSION
docker-desktop-data	Stopped	2
docker-desktop	Stopped	2
Ubuntu	Stopped	1

Ubuntu was restarted from the Windows start apps list. The WSL status was checked again. The status returned showing Ubuntu was running as WSL1. The Docker apps were still WSL2.

PS C:\Users\prior> wsl --list --verbose

NAME	STATE	VERSION
docker-desktop-data	Stopped	2
docker-desktop	Stopped	2
Ubuntu	Running	1

Docker was started and the WSL status checked. It becomes clear that both WSL1 and WSL2 files can be active and running in Windows 10.

PS C:\Users\prior> wsl --list --verbose

NAME	STATE	VERSION
docker-desktop-data	Running	2
docker-desktop	Running	2
Ubuntu	Running	1

Then for the sake of curiosity, Ubuntu was converted back to WSL2 and then started. The status was checked and showed the conversion to WSL2 worked. Ubuntu and Docker are WSL2 and running.

PS C:\Users\prior> wsl --set-version ubuntu 2

Conversion in progress, this may take a few minutes... For information on key differences with WSL 2 please visit https://aka.ms/wsl2 Conversion complete.

PS C:\Users\prior> wsl --list --verbose

NAME	STATE	VERSION
docker-desktop-data	Running	2
docker-desktop	Running	2
Ubuntu	Running	2

It seems clear that it was unnecessary to uninstall and reinstall Linux whenever switching the sub-system for WSL1 or WSL2.