WSL2 Includes a Full Linux Kernel

Date: 09 May 2019

A couple days ago, Microsoft announced WSL2 which includes some pretty big changes. The biggest change is that it includes a full Linux kernel. WSL emulates Linux system calls but WSL2 includes a kernel which will allow it to run significantly more apps, including Docker.

Including a full kernel allows developers to do more Linux development in Windows. This includes running Linux-based Docker containers. That is huge.

I do a lot of work on Linux servers in my job. I’ve been running Linux on my desktop for many, many years. It provides the best environment to work with those servers. With the growth of Docker and containerized services, running Linux on my desktop made even more sense.

At home, it’s a different story. I would still prefer to run Linux but I have software and hardware that requires Windows. I have a removable disk I can boot to, if I need to but it’s really inconvenient if I want to do something quickly. The WSL has made it easier for me to do those quick things. I actually did the full development of the redesign of this site from within the WSL.

The only thing I couldn’t do was easily run containers. One of the things I have working for me on the site is a Docker image I built that includes all of the tools to rebuild the site. Unfortunately, I couldn’t test it or use when I in Windows. WSL2 would make it easier for me to build and deploy those images without leaving Windows.

Obviously, that’s part of Microsoft’s strategy. If they can keep developers in the Windows ecosystem, that’s a win for Microsoft. Still, there are too many applications running in Linux, especially with the explosion of containers, for Microsoft to ignore the need. Heck, I have coworkers who work in Windows that will benefit immensely from WSL2’s Docker capabilities.

WSL2 still runs in a Hyper-V VM but it boots so fast, you can hardly tell. Because it’s more tightly tied to the host Windows system, it allows for better integration with other Windows apps. For organizations that have to run applications on both Windows and Linux, this is a huge win.

Microsoft says that WSL2 should be available though the Windows insider program “by the end of June 2019.” I look forward to using it.