Pro-tip: Look for the -wsl- in the filename. That’s the one optimized for Microsoft’s kernel and integration services. Once you have the 200MB file, open PowerShell as Administrator and run:
Recently, I found myself needing a truly , repeatable , and offline-capable Ubuntu 22.04 (Jammy Jellyfish) environment for a container-like dev environment on Windows. The Microsoft Store version is great, but it comes with baggage: pre-installed snaps, default users, and a specific filesystem layout.
So go ahead. Download the rootfs. Import it. Break it. Reset it. Repeat. That’s the Unix way—even on Windows.
That’s when I fell down the rabbit hole of the . What is a Rootfs Tarball, Anyway? In the WSL world, a "root filesystem" (rootfs) is exactly what it sounds like: the entire / directory of an Ubuntu installation, compressed into a single .tar.gz file. When you feed this tarball to wsl --import , WSL skips the installer, skips the setup wizard, and just unpacks the universe into a new distro.
But for infrastructure engineers, CI/CD pipeline builders, or anyone who hates "magic" black boxes, this tarball is a treasure. It transforms WSL from a fancy GUI app into a genuine infrastructure-as-code tool.
You can find the official Ubuntu WSL rootfs tarballs here: https://cloud-images.ubuntu.com/wsl/
# 1. Create a directory for the distro mkdir C:\WSL\UbuntuJammy wsl --import Ubuntu-Jammy-Custom C:\WSL\UbuntuJammy .\ubuntu-jammy-wsl-amd64-rootfs.tar.gz 3. Launch it as root wsl -d Ubuntu-Jammy-Custom 4. (Optional) Create your non-root user apt update && apt install sudo -y adduser myname usermod -aG sudo myname