Microsoft is backporting WSL2 (Windows Subsystem for Linux 2) to Windows 10 November 2019 Update (version 1909) and the May 2019 Update (version 1903). The support is available for x64 systems. Microsoft said that if you are using an ARM64 version, you will need to upgrade to the most recent version of the operating system, the May 2020 Update (version 2004).
Using a real Linux kernel, WSL2 is a new version that was introduced with v2004, changing how Linux distributions interact with Windows and bringing several improvements. Notably, WSL2 brought in a much faster file system performance and full system call compatibility.
Microsoft wrote that it decided to backport support to ensure WSL2 was available to more Windows 10 users. The support comes through today's Windows 10 update (KB4566116) delivered to both versions 1909 and 1903 and brings all the features of WSL2 to the older OS versions. Some of these include:
File system performance now on par with Mac and Linux speeds
- Improved System Call Support for all Linux applications notably: Docker, FUSE, rsync, etc.
- Full Linux kernel built into WSL 2
- Docker Desktop has added support to use WSL 2 as its engine, giving faster startup speeds and improved resource usage. Please read this blog post on the Docker blog to learn more.
How to get WSL2 on Windows 10 versions 1909 and 1903
To get the support for WSL2 on a device running version 1909 or 1903, you will need to click on the "check for updates" button in Windows Settings to get the latest update. You should be running build 18362.1049 (for version 1903) and build 18363.1049 (for version 1909) to ensure you have this backport. Do note that this is a "preview" update.
You can confirm the build number through Run > type "winver" > hit enter. Once you are on the right build, check this document for installation instructions.