Move WSL File System

WSL has been very useful as a Linux environment running on Windows 10. One problem for WSL is, however, that it is installed to the C drive by default. It would easily take up over 10 GB of space after installing some programming tool chains on it. Recently, my C drive was once again filled by software that can only be installed on C drive. As I browse for files to remove, I found out that my WSL installation was taking 15 GB of storage! After some online search, I managed to move my WSL file system out of C drive. Here is a link to the solution I referred to. I will also briefly talk about it here.

Move WSL File System

::: tip
Note that all commands below should be run in PowerShell
:::

First, list your WSL distros (wsl -l):

PS C:/> wsl -l
Windows Subsystem for Linux Distributions:
Ubuntu20.04 (Default)
Ubuntu-20.04

Take note of the name of the distro you want to move (E.g. Ubuntu-20.04)

Export the distro to a tar file (wsl --export <distro-name> <path-of-tar-file>). E.g.:

PS C:\> wsl --export Ubuntu-20.04 E:\ubuntu-wsl.tar

After the export finishes, import the tar file to your desired location (wsl --import <distro-name> <path-of-desired-location> <path-of-tar-file>). E.g.:

PS C:\> wsl --import Ubuntu20.04 E:\WSL\Ubuntu20.04 E:\ubuntu-wsl.tar

After this is done, test the new distro with wsl -u <username> -d <distro-name>. E.g.:

PS C:\> wsl -u rochor -d Ubuntu20.04

If it works as intended, you can then safely remove the original distro (wsl --unregister <distro-name>). E.g.:

PS C:\> wsl --unregister Ubuntu-20.04
PS C:\> wsl -l # make sure the distro was successfully unregistered

Then, change the default user of your newly created distro. You may refer to this issue comment. E.g.:

Function WSL-SetDefaultUser ( $distro="<DistroName>",$ user="<UserName>") { Get-ItemProperty Registry::HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Lxss\*\ DistributionName | Where-Object -Property DistributionName -eq  $distro | Set-ItemProperty -Name DefaultUid -Value ((wsl -d$ distro -u $user -e id -u) | Out-String); }; WSL-SetDefaultUser Ubuntu20.04 rochor; Remove-Item Function:WSL-SetDefaultUser;

Now you have a working WSL distro that is not in C drive!