Overview

In this post, we’ll cover how to duplicate an existing WSL Linux distrbution.

Background

For WSL2 distributions managed by Microsoft, you can simply pull down the latest bundled distro when you need it and it’s made available.

For distributions you may have hand-rolled or pulled from other locations, you may need to do perform some additional intervention if you want to retain multiple copies of a release. For example I have a Fedora 38 distribution built based on Install Fedora 37 or earlier on Windows Subsystem for Linux (WSL), and at time of writing Fedora 40 is current. I could do an in-place upgrade of F38 -> F40, but I may wish to retain copies of both releases (or any other intermediate upgrade points should I choose).

In order to do this we can follow a process similar to Duplicate a Linux distro under WSL2:

  1. Clone F38 -> F38.copy
  2. Upgrade f38.copy -> F40
  3. …
  4. Profit

How-to

Windows

On your Windows system:

  1. Verify your current installed WSL distribution(s): 
     PS C:\Users\wmcdonald> wsl -l
 Windows Subsystem for Linux Distributions:
 docker-desktop-data (Default)
 Fedora-38
 Ubuntu-22.04
 docker-desktop

    Note: You can identify the underlying disk location of your WSL distributions by running Get-ChildItem "HKCU:\Software\Microsoft\Windows\CurrentVersion\Lxss" -Recurse

  2. Create a directory to hold our intermediate distribution image(s): 
     PS C:\Users\wmcdonald> New-Item -Type Directory d:\wsl\distros\
  3. Export a tar archive/image of the target distribution: 
     PS C:\Users\wmcdonald> wsl --export Fedora-38 D:\wsl\distros\Fedora-38.tar
 The operation completed successfully.
  4. Import the distro as a new distribution/profile: 
     PS C:\Users\wmcdonald> wsl --import Fedora-40 C:\Users\wmcdonald\wsl\Fedora-40 D:\wsl\distros\Fedora-38.tar
 Import in progress, this may take a few minutes.
 The operation completed successfully.

    Note: We could just as easily have a single ‘Fedora’ or ‘Fedora-Latest’ distro profile which we constantly upgrade in-place if we don’t care about the availability of previous releases.

  5. We can now start the new distribution: 
     PS C:\Users\wmcdonald> wsl -d Fedora-40 -u wmcdonald
 [wmcdonald@DESKTOP-9HGJE25 wmcdonald]$

  6. Create a new Windows Terminal profile for Fedora-40.

    TODO: Programmatically add the distribution as a new profile in the Windows Terminal.

WSL

In your WSL2 instance:

  1. Now in-place upgrade the distribution from Fedora-38 -> Fedora-40 
     [wmcdonald@DESKTOP-9HGJE25 ~]$ sudo su -
 [root@DESKTOP-9HGJE25 ~]# dnf upgrade -y --refresh
 [root@DESKTOP-9HGJE25 ~]# dnf install dnf-plugin-system-upgrade
 [root@DESKTOP-9HGJE25 ~]# dnf system-upgrade download --releasever=40
 [root@DESKTOP-9HGJE25 ~]# export DNF_SYSTEM_UPGRADE_NO_REBOOT=1
 [root@DESKTOP-9HGJE25 ~]# dnf system-upgrade reboot
 [root@DESKTOP-9HGJE25 ~]# dnf upgrade --refresh

Further reading