WSL: Restoring a Distro from a Backup

This article discusses restoring a WSL distro from a backup TAR file. In a previous entry, the backup process for a WSL distro was presented: WSL: Backing Up and Deleting a Distro. Restoring from a backup is a bit more complicated because the wsl --import command requires that the "install location" be specified, but knowing where the default path used by WSL to install virtual disks (*.vhdx files) is important.

Microsoft documentation, Import any Linux distribution to use with WSL, presents the full wsl --import command as follows:

wsl.exe --import <Distro> <InstallLocation> <FileName> [Options]
Options:
    --version <Version>
    --vhd

To see the location where virtual disks are stored, run the following from a PowerShell console window:

$regKeyPath = 'HKCU:\Software\Microsoft\Windows\CurrentVersion\Lxss'

Get-ChildItem $regKeyPath |

  Get-ItemProperty |

  Select-Object DistributionName, BasePath

An example of the output from the above command is as follows:

DistributionName    BasePath

----------------    --------

docker-desktop      \\?\C:\Users\jann\AppData\Local\Docker\wsl\distro

docker-desktop-data \\?\C:\Users\jann\AppData\Local\Docker\wsl\data

Ubuntu-24.04        C:\Users\jann\AppData\Local\wsl\{e3757a3a-1cb5-4208-b9c2-5f6f7490cda8}

From the above output, the default location used by WSL is:

C:\Users\jann\AppData\Local\wsl

Notice the GUID in the path, meaning WSL creates a random folder name — a GUID (e.g., {e3757a3a-1cb5-4208-b9c2-5f6f7490cda8}) — for the distro instance.

C:\Users\jann\AppData\Local\wsl\{e3757a3a-1cb5-4208-b9c2-5f6f7490cda8}

For the sake of example, the following InstallLocation could be used when importing an instance of Ubuntu-24.04:

C:\Users\jann\AppData\Local\wsl\Ubuntu-24.04Host00

The distro name must be unique so run the following comment to see the current distros installed.

wsl -l -v

An example of the output generated by wsl -l -v is as follows:

  NAME                   STATE           VERSION

* docker-desktop         Stopped         2

  docker-desktop-data    Stopped         2

  Ubuntu-24.04           Running         2

From the list of names, choosing Ubuntu-24.04 as the name for the imported distro would be invalid.

For our example, the following parameters will be used:

• Distro Ubuntu-24.04Host00
• InstallLocation: C:\Users\jann\AppData\Local\wsl\Ubuntu-24.04Host00
• FileName: C:\Backups\20250921Ubuntu-24.04.tar

In the blog, WSL: Backing Up and Deleting a Distro, a backup TAR file named 20250921Ubuntu-22.04.tar was created. The steps described in the blog were used to create a backup of a clean Ubuntu-24.04 WSL distro and the full back up file was placed at:

C:\Backups\20250921Ubuntu-24.04.tar

The full command to import the back up is as follows:

wsl --import Ubuntu-24.04Host0 'C:\Users\jann\AppData\Local\wsl\Ubuntu-24.04Host00' 'C:\Backups\20250921Ubuntu-24.04.tar'

The import took tens of seconds compared to the export, which took minutes. Once complete, wsl --import displays status:

The operation completed successfully.

After import, always verify by running, wsl -l -v, which shows Ubuntu-24.04Host0 was created:

  NAME                   STATE           VERSION

* docker-desktop         Stopped         2

  Ubuntu-24.04Host0      Stopped         2

  docker-desktop-data    Stopped         2

  Ubuntu-24.04           Stopped         2