Table of contents
Introduction
The root filesystems are located in $env:LOCALAPPDATA\Wsl\RootFS. Each root file system is stored as a file with the rootfs.tar.gz suffix.
Some root filesystems may be compressed with other formats than gunzip. However, the file suffix is still tar.gz and WSL will recognize it.
Along with each root filesystem file, there is a json file containing metadata information for the root filesystem. this file ends with the rootfs.tar.gz.json suffix.
Types of root filesystems
Root filesystems can currently be of the following types:
Builtin
These are the filesystems that can be used by their name. Currently there is:
- Archlinux. As this is a rolling distribution, there is no version attached. The current image used as base is 2025-08-01.
- Alpine (3.22)
- Ubuntu (25.10 questing)
- Debian (13 trixie)
- OpenSuse (tumbleweed). This is also a rolling distribution.
Each of these distributions comes into 2 flavors: Un-configured (the default) and Configured. The configured version of the root filesystem has been already configured through a github actions workflow
Incus
Incus, or linux containers, is a solution to run Linux system containers on a Linux machine. It’s somewhat like WSL for Linux, but with more features. Canonical maintains root filesystems and images for a fair amount of linux distributions (list here).
The list of available Incus root filesystems can be obtained with the command:
PS> Get-IncusRootFileSystem
Os Release
-- -------
almalinux 8
almalinux 9
...
ubuntu xenial
voidlinux current
A Incus based WSL distribution can be created with Install-Wsl by passing a distribution name with the form:
incus:<os>:<release>
for instance:
PS> Install-Wsl test -Distribution incus:rockylinux:9 -SkipConfigure
...
Wsl-Manager will fetch the root filesystem for the corresponding distro from https://images.linuxcontainers.org/images.
Local
A local root filesystem is only available locally. It is the result of an Export-Wsl command (more information here).
Uri
The Uri type of distributions is for distributions that have been installed from a URL. For instance:
PS> Install-Wsl test -Distribution https://downloads.openwrt.org/releases/22.03.2/targets/x86/64/openwrt-22.03.2-x86-64-rootfs.tar.gz -SkipConfigure
####> Creating directory [C:\Users\AntoineMartin\AppData\Local\Wsl\test]...
####> Downloading https://downloads.openwrt.org/releases/22.03.2/targets/x86/64/openwrt-22.03.2-x86-64-rootfs.tar.gz => C:\Users\AntoineMartin\AppData\Local\Wsl\RootFS\openwrt-22.03.2-x86-64-rootfs.tar.gz...
####> Creating distribution [test] from [C:\Users\AntoineMartin\AppData\Local\Wsl\RootFS\openwrt-22.03.2-x86-64-rootfs.tar.gz]...
####> Done. Command to enter distribution: wsl -d test
PS> Get-WslRootFileSystem -Type Uri
Type Os Release State Name
---- -- ------- ----- ----
Uri openwrt unknown Synced openwrt-22.03.2-x86-64-rootfs...
PS>
Docker/OCI Images
Root filesystems can also be downloaded from Docker/OCI compatible registries like GitHub Container Registry (ghcr.io). This functionality is built into the module for accessing container images that contain root filesystems as single layers.
When using Docker URIs with the format docker://registry/image:tag, the module will:
- Authenticate with the registry
- Download the image manifest
- Extract the single layer containing the root filesystem
- Save it as a compressed tar.gz file
This is particularly useful for accessing root filesystems built and distributed as container images.
Get root filesystems
The list of root filesystems is given by the Get-WslRootFileSystem command:
PS> Get-WslRootFileSystem
Type Os Release State Name
---- -- ------- ----- ----
Builtin Alpine 3.19 Synced alpine.rootfs.tar.gz
Builtin Arch current Synced arch.rootfs.tar.gz
Builtin Debian bookworm Synced debian.rootfs.tar.gz
Local Docker unknown Synced docker.rootfs.tar.gz
Local jekyll 3.19.1 Synced jekyll.rootfs.tar.gz
Builtin Alpine 3.19 Synced miniwsl.alpine.rootfs.tar.gz
Builtin Arch current Synced miniwsl.arch.rootfs.tar.gz
Builtin Debian bookworm Synced miniwsl.debian.rootfs.tar.gz
Builtin Opensuse tumbleweed Synced miniwsl.opensuse.rootfs.tar.gz
Builtin Ubuntu noble NotDownloaded miniwsl.ubuntu.rootfs.tar.gz
Local Netsdk unknown Synced netsdk.rootfs.tar.gz
Builtin Opensuse tumbleweed Synced opensuse.rootfs.tar.gz
Uri openwrt unknown Synced openwrt-22.03.2-x86-64-rootfs...
Local Postgres unknown Synced postgres.rootfs.tar.gz
Builtin Ubuntu noble Synced ubuntu.rootfs.tar.gz
PS>
Several filters are available (see reference), like:
PS> Get-WslRootFileSystem -Os alpine
Type Os Release State Name
---- -- ------- ----- ----
Builtin Alpine 3.19 Synced alpine.rootfs.tar.gz
Builtin Alpine 3.19 Synced miniwsl.alpine.rootfs.tar.gz
You can also get only outdated root filesystems (mainly for Builtin distributions):
PS> Get-WslRootFileSystem -Outdated
Type Os Release State Name
---- -- ------- ----- ----
Builtin Ubuntu noble Outdated ubuntu.rootfs.tar.gz
Synchronize root filesystems
Local Synchronization of root filesystems is performed with the Sync-WslRootFileSystem cmdlet. For instance:
PS> Sync-WslRootFileSystem -Distribution ubuntu -Configured
Downloading docker://ghcr.io/antoinemartin/powershell-wsl-manager/miniwsl-ubuntu#latest to C:\Users\AntoineMartin\AppData\Local\Wsl\RootFS\miniwsl.ubuntu.rootfs.tar.gz with filename miniwsl-ubuntu
⌛ Downloading Docker image layer from ghcr.io/antoinemartin/powershell-wsl-manager/miniwsl-ubuntu:latest...
⌛ Getting docker authentication token for registry ghcr.io and repository antoinemartin/powershell-wsl-manager/miniwsl-ubuntu...
⌛ Getting image manifests from https://ghcr.io/v2/antoinemartin/powershell-wsl-manager/miniwsl-ubuntu/manifests/latest...
⌛ Getting image manifest from https://ghcr.io/v2/antoinemartin/powershell-wsl-manager/miniwsl-ubuntu/manifests/sha256:c534fd74c...
👀 Root filesystem size: 75,2 MB. Digest sha256:123... Downloading...
sha256:123... (75,2 MB) [=======================================================================================================================] 100%
🎉 Successfully downloaded Docker image layer to C:\Users\AntoineMartin\AppData\Local\Wsl\RootFS\miniwsl.ubuntu.rootfs.tar.gz.tmp
👀 Downloaded file size: 75,2 MB
🎉 [Ubuntu:noble] Synced at [C:\Users\AntoineMartin\AppData\Local\Wsl\RootFS\miniwsl.ubuntu.rootfs.tar.gz].
C:\Users\AntoineMartin\AppData\Local\Wsl\RootFS\miniwsl.ubuntu.rootfs.tar.gz
PS> Get-WslRootFileSystem -Os ubuntu
Type Os Release State Name
---- -- ------- ----- ----
Builtin Ubuntu noble Synced miniwsl.ubuntu.rootfs.tar.gz
Builtin Ubuntu noble Synced ubuntu.rootfs.tar.gz
You can also synchronize a root filesystem from a local file path:
PS> Sync-WslRootFileSystem -Path "C:\path\to\custom.rootfs.tar.gz"
You can force the re-synchronization with the -Force switch. For instance, to force re-synchronization of the builtin Alpine root filesystems:
PS> Get-WslRootFileSystem -type builtin -Os alpine | Sync-WslRootFileSystem -Force
Downloading https://dl-cdn.alpinelinux.org/alpine/v3.22/releases/x86_64/alpine-minirootfs-3.22.1-x86_64.tar.gz to C:\Users\AntoineMartin\AppData\Local\Wsl\RootFS\alpine.rootfs.tar.gz with filename alpine-minirootfs-3.22.1-x86_64.tar.gz
⌛ Downloading https://dl-cdn.alpinelinux.org/alpine/v3.22/releases/x86_64/alpine-minirootfs-3.22.1-x86_64.tar.gz...
alpine-minirootfs-3.22.1-x86_64.tar.gz (3,3 MB) [================================================================================================================] 100%
🎉 [Alpine:3.22] Synced at [C:\Users\AntoineMartin\AppData\Local\Wsl\RootFS\alpine.rootfs.tar.gz].
C:\Users\AntoineMartin\AppData\Local\Wsl\RootFS\alpine.rootfs.tar.gz
Downloading docker://ghcr.io/antoinemartin/powershell-wsl-manager/miniwsl-alpine#latest to C:\Users\AntoineMartin\AppData\Local\Wsl\RootFS\miniwsl.alpine.rootfs.tar.gz with filename miniwsl-alpine
⌛ Downloading Docker image layer from ghcr.io/antoinemartin/powershell-wsl-manager/miniwsl-alpine:latest...
⌛ Getting docker authentication token for registry ghcr.io and repository antoinemartin/powershell-wsl-manager/miniwsl-alpine...
⌛ Getting image manifests from https://ghcr.io/v2/antoinemartin/powershell-wsl-manager/miniwsl-alpine/manifests/latest...
⌛ Getting image manifest from https://ghcr.io/v2/antoinemartin/powershell-wsl-manager/miniwsl-alpine/manifests/sha256:ec906d1cb2f8917135a9d1d03dd2719e2ad09527e8d787434f0012688111920d...
👀 Root filesystem size: 35,4 MB. Digest sha256:a10a24a60fcd632be07bcd6856185a3346be72ecfcc7109366195be6f6722798. Downloading...
sha256:a10a24a60fcd632be07bcd6856185a3346be72ecfcc7109366195be6f6722798 (35,4 MB) [=======================================================================================================================] 100%
🎉 Successfully downloaded Docker image layer to C:\Users\AntoineMartin\AppData\Local\Wsl\RootFS\miniwsl.alpine.rootfs.tar.gz.tmp
👀 Downloaded file size: 35,4 MB
🎉 [Alpine:3.22] Synced at [C:\Users\AntoineMartin\AppData\Local\Wsl\RootFS\miniwsl.alpine.rootfs.tar.gz].
C:\Users\AntoineMartin\AppData\Local\Wsl\RootFS\miniwsl.alpine.rootfs.tar.gz
PS>
Remove Root filesystems
You can remove local root filesystems with the Remove-WslRootFileSystem cmdlet:
PS> Remove-WslRootFileSystem -Distribution opensuse
Type Os Release State Name
---- -- ------- ----- ----
Builtin Opensuse tumbleweed NotDownloaded opensuse.rootfs.tar.gz
It can accept the root filesystem through the pipe:
PS> Get-WslRootFileSystem -Os opensuse | Remove-WslRootFileSystem
Type Os Release State Name
---- -- ------- ----- ----
Builtin Opensuse tumbleweed NotDownloaded miniwsl.opensuse.rootfs.tar.gz
PS> Get-WslRootFileSystem -Os opensuse
Type Os Release State Name
---- -- ------- ----- ----
Builtin Opensuse tumbleweed NotDownloaded miniwsl.opensuse.rootfs.tar.gz
Builtin Opensuse tumbleweed NotDownloaded opensuse.rootfs.tar.gz
Get root filesystems by size
You can order the present filesystem by size with the command:
PS> Get-WslRootFileSystem -State Synced| Sort-Object -Property Length -Descending | Format-Table Type, Os, Release, Configured, @{Label="Size (MB)"; Expression={ [int]($_.Length/1Mb) }}
Type Os Release Configured Size (MB)
---- -- ------- ----------------- ---------
Local Netsdk unknown True 477
Local Docker unknown True 465
Builtin Ubuntu noble False 429
Local Postgres unknown True 361
Builtin Arch current True 328
Builtin Arch current False 173
Local jekyll 3.19.1 True 168
Builtin Debian bookworm True 125
Builtin Opensuse tumbleweed True 98
Builtin Opensuse tumbleweed False 43
Builtin Debian bookworm False 32
Builtin Alpine 3.19 True 26
Builtin Alpine 3.19 False 3