Windows Subsystem for Linux (WSL) - Simply Explained

0:00 Welcome to the M365 FM podcast where we explore the people, ideas and technologies shaping the future of work. Why Linux tools keep showing up in windows tutorials. Half the tutorials online assume you're not on windows, and that used to mean you had the wrong machine. Windows now ships a free feature that runs real Linux right beside it, built into windows ten and eleven. You might think it's a virtual machine you have to babysit, but it starts in under a second. By the end, you'll know how it really works, where it slows you down, and how it fits into Azure. Welcome to the M365 FM podcast, where we explore the people, ideas, and technologies shaping the future of work. You have probably hit this wall already. A tutorial you actually want to follow reads fine, right up until step two. That is where it asks you to open a terminal and type a command into something called bash.

0:43 Your laptop runs windows, so you close the tab and go hunting for a windows version of that tutorial, which was never written. That gap is the problem. WSL was built to close. The feature has been sitting on your machine since twenty sixteen, and it goes by the name Windows Subsystem for Linux. The name is a mouthful, so everyone just calls it w s l. This episode is the plane tour and you won't need an IT background to follow along. What w s l actually is. The name sounds heavier than the thing itself. W s l is a windows feature that runs a Linux environment right on your PC. It does that without a separate virtual machine, and it does it without wiping your drive to install a second operating system. The first thing you get is a real command line shell, which is a text window where you type instructions instead of clicking buttons.

1:23 The second thing is genuine Linux software that installs and runs the way it would on a Linux machine. You also pick a distribution, which is just a flavor of Linux, like ubuntu, Debian, or Kali. Each distribution gets its own separate file system for Linux files live in one place, and your windows files live in another, and the two stay apart unless you deliberately connect them. Ubuntu is the default, and you can install more than one distribution if you want to compare them. Debian and Kali sit right there in the list ready to add. Updates come from the Microsoft Store, just like a normal app on your machine. One detail surprises people once they look it up. The Linux kernel that Wsl2 runs is built by Microsoft, tuned for windows and serviced through regular windows updates in twenty twenty five. Microsoft also published the source code on GitHub, so anyone can read how it works or send in a fix.

2:06 You don't need any of that to use w s l, but it explains why the tool keeps getting better without you lifting a finger. If the built in list isn't enough, you can import a distribution that isn't in the store or build your own from scratch. That matters when a project needs one specific setup that nobody publishes for you, it costs nothing. W SL comes with windows ten and windows eleven, and it even runs on the home edition that ships on cheap laptops. Picture a door, not a second computer. You stay in windows the whole time, and when you need Linux tools, you step through the real difference between W s l one and w s l two w s l has shipped in two versions, and knowing the difference saves you a pile of confusion. The first one, w s l one, translated Linux commands into something windows could understand.

2:48 That translation worked for simple tasks. It was still a translation, though, so anything complicated eventually ran into a wall. That wall is the reason w s l two exists. Instead of translating w s l two runs a real Linux kernel. The kernel is the core of the operating system, and it sits inside a small virtual machine that windows starts and stops for you because it's the genuine kernel. Linux software behaves the way its creators intended. You might hear the words virtual machine and picture something heavy. That instinct is fair because traditional virtual machines are heavy. This one isn't. It's lightweight. It boots in seconds, not minutes, and you never open a settings panel to keep it alive. The two versions are more than a technical footnote, because w, s, l has a short history worth knowing. Microsoft first put Linux tools on windows back in twenty sixteen, then announced the kernel based version in twenty nineteen.

3:33 Later, it moved the whole thing out of the windows image and into the Microsoft Store. That led the team ship fixes on their own schedule. The payoff shows up as speed and compatibility. Early Wsl2 ran up to twenty times faster than w s l one. When unpacking a zip tarball. It was roughly two to five times faster on everyday chores like cloning a project or installing packages. Full system call compatibility means Linux software just runs, and that includes Docker, the tool developers use to package apps into portable boxes. One quirk is worth flagging if you already run other virtualization software. W s L1 played nicely with VMware and VirtualBox, and WSL two historically didn't. Though recent releases of those tools have caught up. Check that detail before you switch on a laptop you use for other virtual machines.

4:14 WSL two is the default today, so a fresh install gives you the newer version. Exactly. One case still favors the older one, and it's worth remembering for later. That case is files which have to live on your windows drive. Installing it in one command. The install really is one command, and the details matter here. First, check that your running windows ten version two thousand and four or newer, or windows eleven. Then open PowerShell as an administrator, type w, s, l install and restart your machine. That single line switches on the two windows features W, s, L needs, and it adds ubuntu as your first Linux distribution. The two features it switches on are called Virtual Machine Platform and Windows Subsystem. For Linux, you can turn those on by hand if the one command route ever fails on you.

4:54 W s l runs on regular Intel and AMD chips and on the arm chips inside some thin laptops, so your hardware is rarely the blocker. Ubuntu is just the starting point, not the only choice. If you would rather begin with Debian Kali or something else, you add that distribution name to the end of the same command. You can also browse a list to see everything available. The first launch of your new Linux setup takes a moment because it unpacks files onto your disk. Every launch after that happens in less than a second. That speed is what makes it feel less like a separate machine and more like a tab in your terminal. Once everything is set up, you can see what you have by asking w, s, l to list your distributions with their version numbers. You can also move a distribution between the two versions at any time, which is handy when you want to test a difference yourself.

5:35 Updates now work like an app rather than a piece of windows itself. New features arrive through the Microsoft Store without waiting on a full Windows update. If your company blocks the store, there's a web download option that still works. Work laptops come with an honest catch. Some organizations block w, cell through a group policy. When that happens, the install fails with a long error code instead of a friendly message. That block is a company decision, not a broken laptop, and only your IT team can lift it. How Linux and Windows share your files. This is the part that causes the most confusion and frustration, because it comes down to where your files actually live. Windows and Linux keep files in two different places. Cell lets each site see the other, but the two sides aren't equally fast. Your windows drives show up inside Linux under a folder called mnt.

6:17 Your C drive, for example, appears as mnt C, and from there you can read and write any windows file you like. The other direction works too, because windows can browse into the Linux file system through a special address, you can paste into File Explorer. Linux files follow a different set of rules. Anything under the Linux root is case sensitive, so two files with the same letters, but different capital letters count as different files. Symbolic links behave the way Linux expects, and commands like chmod and chown actually mean something. Windows files don't work that way, and that difference is where the slowdowns hide. downside. Microsoft is direct about this in its own documentation. The guidance is to store your files in the same operating system as the tools you use on them. The same page also warns against crossing the boundary unless you have a specific reason.

6:59 In plain terms, when the tools are Linux tools, keep the project inside Linux. If you're working in PowerShell or a windows app, keep it on the windows side. The reason matters because it explains a complaint you will hear from everyone. Reading and writing across that boundary is the slow path. It hurts most when a project is built from thousands of tiny files because each one pays the crossing cost. A single document crosses just fine, but a folder full of downloaded packages will crawl. The common case has a clean fix. The remote w s l extension for Visual Studio code lets you keep your project inside the Linux file system. You still edit those files with a windows editor, so you get Linux speed without giving up your usual tools. You can mix commands freely as well run notepad from Linux, or run a Linux command straight from PowerShell and both feel natural after a day or two, a shared variable called W, s, l, v passes environment settings across the divide, which saves you from retyping the same paths on both sides.

7:49 Two habits save beginners a lot of grief. Keep Linux projects inside Linux and Windows projects on the windows side, which we just covered. Then export your Linux setup now and again, because it lives inside a single large file that you can back up, move, or restore on another machine. What you can actually do with it once the files behave. The interesting part starts because this is a full Linux environment, it runs the same tools a Linux server runs, and that list is long. You get the classic command line utilities like grep, s, awk, vim, and tmux. You get the languages and stacks that assume Linux, including node, Python, Ruby, go rust, and the C family services work too. You can run MySQL, PostgreSQL, or MongoDB inside W, s, L and start a small web server.

8:30 Then you reach it from your windows browser by typing localhost, which means a practice project doesn't need its own machine. Graphical Linux apps are supported as well. They open as ordinary windows on your desktop, so a Linux text editor or a data tool sits in the taskbar beside your usual apps. If your work touches machine learning. W s l can hand your graphics card to Linux workloads. That is how people train models on a windows laptop without giving up. Windows containers deserve their own moment because this is where WSL became the standard. Docker on windows runs on top of WSL two, and that's only possible because WSL two has a genuine Linux kernel underneath. If you have ever installed Docker desktop on windows, you have already been using WSL without knowing it. To make this concrete, try a small project this week, pick a beginner tutorial for Python or Node and follow it inside WSL.

9:15 Skipping the windows workarounds install the packages it asks for, then run it. You will type the exact same commands the tutorial author used, which is the entire point. Editors and databases round this out nicely. Visual Studio Code can open your Linux files directly. A database for a side project can also live inside WSL instead of on a separate server you would otherwise rent. Microsoft's own example of this pattern starts with a developer who builds and tests a pipeline locally. That pipeline gets packaged into a container and pushed to the cloud where it runs on a Linux virtual machine that is the shape of modern software work, and w s L is the local half of it. The catch is that all of this comes with a few real limits, and those are next where it breaks and what to watch out for. Now for the honest part. Because a tool you don't understand will surprise you in a bad way.

9:58 W s l is genuinely good and it also has specific limits. Knowing them ahead of time is what separates a smooth setup from a frustrating afternoon. Memory is the first surprise by default. W s l two is allowed to use up to half of your windows memory, and it can hold on to cached memory until the whole instance shuts down. On a long session with a big project, task manager can look like something ate your ram. The fix is a small settings file where you can keep memory and processes. An automatic memory reclaim option exists for exactly this problem. The defaults are worth putting numbers on a laptop with sixteen gigabytes of memory. Hands eight of those gigabytes to Linux by default. It also adds a swap file sized at a quarter of your memory, which lives on disk and acts as overflow. You can lower those numbers, raise them, or turn swap off entirely in the same settings.

10:42 File changes take effect after the Linux side fully restarts, which takes a few seconds. The second surprise is that the machine underneath cell starts and stops on its own. If nothing is using it, it shuts down to save resources. That is confusing. When a local server suddenly stops answering. Closing the last terminal window triggers the shutdown, so keep one open if you want things to stay up. Disk space has a quirk of its own. The Linux side lives inside one large storage file that grows as you add data. An experimental setting lets that file shrink again when you delete things instead of holding on to the space forever. Which brings us to the biggest limit of all. And Microsoft says it plainly w s l is built for the build and test cycle on your own machine, and it isn't a production server. There is a way to use its container technology for production work, but the safe rule for a beginner is simple use w s l to build and learn.

11:28 Use a real Linux machine or a cloud service to serve real users. Networking has its own quirks. By default, w SL uses a setup called Nat, which gives your Linux site its own address, reaching it from another device on your network used to take manual work on windows eleven, and newer mirrored mode fixes this. It also improves how WSL behaves on a VPN, which matters if you work from home on a company network. A few smaller things are worth knowing. Windows folders get added to the Linux path automatically, and Linux can launch windows programs, so WSL isn't a byte for byte copy of a Linux machine. Serial ports aren't supported, and USB devices need a separate helper project. Some third party security suites, including Kaspersky, AVG, Avast, Symantec, and F-Secure, have been reported to block internet access inside W, s l. If your Linux side suddenly has no internet, check your firewall first.

12:14 None of that should scare you off. Every limit here has a known cause or a workaround. The point is to know the shape of the tool before you lean on it. How WSL fits into Azure and Microsoft three hundred sixty five. The question. A lot of people in the Microsoft world actually care about deserves a straight answer. W s l ships as part of windows itself. Nothing here is part of a Microsoft three hundred sixty five plan or an Azure subscription, and it doesn't add a line to your bill if you're on windows ten or windows eleven, the feature is already there. So where does the cloud come in? The connection is a workflow, not a license. Linux runs a huge share of the servers in the cloud, and Azure is no exception. The same commands you learn locally are the commands that deploy and manage real cloud systems. The practical version looks like this. The Azure command line tool called the Azure CLI, installs and runs inside W s L exactly as it does on Linux.

13:00 Microsoft documents how to install it on Linux, and it even keeps a troubleshooting page for w s l. Specifically, after it is installed, you can sign into Azure and manage resources from the same terminal where you were running Linux commands a minute earlier. The tool also updates itself in one step, so you're not stuck on an old version. Microsoft has also brought its own Linux distribution into the picture. Azure Linux is the distribution Microsoft builds for Azure. You can now run it on WSL as a local environment, and it uses the same tools and the same behavior it has in the cloud. No virtual machine is involved and no Azure subscription is required. That closes a gap which used to cause real pain where something worked on your laptop and broke the moment it reached the server. That consistency matters most for teams. When the environment a developer tests against matches the environment the workload runs in.

13:43 Fewer surprises survive the trip to production for a slow learner. The same idea is a cheap way to practice with the exact tools a cloud job would expect you to know for the Microsoft three hundred sixty five crowd. Specifically, I want to set expectations. W s l is the workshop next door, the place where scripts, pipelines, and cloud tools get built and tested before they touch anything real. If you're building a career around the Microsoft cloud, that workshop is worth learning your way around the short version and a question for you. That's the whole thing. In a few lines, w s l puts a working Linux environment on your laptop and it's free and already there. It installs with a single command, and its main quirk is that files crossing between the two systems move slowly. Here's my question for you. Is there a tutorial you have been skipping because it looked like it was written for Linux?

14:25 And would you try it? Now that you know w s l is sitting there? If this made the topic feel less intimidating, subscribe to M365 FM to master the tools and the mindset shaping the future of work.