WSL Manager(github.com) |
WSL Manager(github.com) |
I recently realized that 100% of what I use Windows for was as a WSL2 foundation: It had been reduced to being an extremely overbearing and heavyweight host machine for a Linux VM. Nothing in my life was Windows-only anymore, and it was basically just inertia that I even still had it installed.
I'd been a "Windows guy" for decades, had decades of Windows software dev under my belt, even got my MCSE, MCDBA, along with other Microsoft certs, and even wrote for MSDN Magazine. No longer did it have any leverage on my profession at all, which was shocking to me.
The next day I purged Windows from my two main working machines, so now I'm pure Linux and macOS. A few weeks later and I can say it has been a marvelous transition, and cuts out the no longer relevant middleman.
_However_, still find the Linux desktops that I've tried are too buggy. While the hardware support is incredible (compared to Windows out of the box), I constantly hit bugs with fractional scaling on multiple monitors. I'm hopeful that Ubuntu 26.04 may finally iron out the last problems with this. The latest version of Fedora I installed did fix all this but I'm far too used to Debian based OSes.
Well, even Microsoft uses React Native for a lot of Windows-only apps.
VirtualBox has really broken graphics support, you can only run software rendering Linux DEs that way.
There are projects like this https://github.com/jamesstringer90/Easy-GPU-PV that you can use to setup a Hyper-V machine to use the same paravirtualization.
> Automatically Installs Windows to the VM
This seems to be focused on Windows guests. I need this for Linux guests.
May be when Hyper-V will make this usable out of the box for any guests, I'll take a look. And if it's something shareable, may be VirtualBox should pick that up.
I'm not using X, I need a normal KDE Wayland session.
I've tried Optimize-VHD but renewing the VM this way frees up disk and speeds up the VM as well. None of the WSL settings for sparse disk / disk shrinking seem to work well.
Here's what I usually do
$ tar -czf /mnt/c/Temp/home-backup.tgz $HOME
$ apt list --installed > /mnt/c/Temp/packages.txt
$ tar -cxf /mnt/c/Temp/home-backup.tgz -C $HOME
$ apt update
$ cat /mnt/c/Temp/packages.txt | xargs apt installStill, thanks for the process you use.
My wsl is pretty long lived now, through quite a few ubuntu upgrades and installations of stuff that I probably no longer need.
No matter what you do, there will always be some weird platform detection or line termination that pops up somewhere. And if it isn’t that, it’s degraded performance or kernel-level incompatibility.
The only reason I use Windows is because Nvidia drivers are easier to setup. But once I'm inside my Fedora WSL, that feels like home, not the Windows host.
Thus React Native is the only alternative left those teams had to have some kind of nice GUI design experience alongside C++/WinRT, when using WinAppSDK, think Qt with QML/C++.
Agree on the Flutter comment.
I know I'm beating a dead HN horse here, but how the hell is it possible that megabytes of embedded JavaScript in websites, to the point that LinkedIn uses about half the RAM I had for my first computer loading 32 MB of JavaScript files. Jjira loads 50 (!) MB of javascript, enough to include the uncompressed version of War and Peace 16 times. That's the size of a full installation of the entire Windows 95 operating system. GitLab's static landing page is 13MB of JavaScript, larger than that of Twitter.
What the hell are we doing here? Why can I spin up a 100 MHz, 8MB RAM VM with a hard drive size that's 1/16th of your entry level MacBook's RAM and have apps open immediately? I understand some backsliding as things get more high level, but a website loading 50 megabytes of JavaScript, to me, is like a bright neon sign that screams "something has gone wrong terribly here". Obviously programs, websites and operating systems have become incredibly more complex but your $200 A-series Samsung phone has about 8 cores at 2.2 GHz each. A $200 processor when Windows 95 was released had one core at 0.1GHz. making the processing power about 164x faster. Keep in mind this $200 includes a fully functioning computer in the palm of your hand. The actual CPU part for a midrange phone like the Samsung A15 5G is the Dimension 6100+, which costs all of $25 bucks.
There must be some sort of balance between ease of prototyping, creating and deploying an application without bundling it with Electron or building websites that use tens of megabytes of a scripting language for seemingly nothing. Especially when we can see that a fast, usable website (see this very website or the blogs of many of the people who post here, compared to Reddit for your average medium or substack blog).
How the hell do we fix this? The customers clearly don't want this bloat, companies clearly shouldn't want it either (see research that indicates users exposed to a 200 millisecond load delay on Google, performed 0.2-0.6% fewer searches, and effect that remained even when the artificial delay was removed. This was replicated by Microsoft, Amazon and others. It's frequently brought up that Amazon has said that every 100 milliseconds of page load time cost them 1% in sales, though it's hard to find definitive attribution to this), programmers should hopefully not want to create crappy websites just like mechanics should hopefully not want to install brake pads that squeal every time the user breaks.
This got way longer than the two sentences I expected the post to be, so my apologies.
[1] https://tonsky.me/blog/js-bloat/ [2] Velocity and the Bottom Line, Shurman and Brutlag
Both of these statements are false. If this was really the case, then competing company/dev could implement native counterpart and just siphon all the users – I've only seen this happen with CLI tools (e.g. esbuild, rollup, uv, etc.)
citation needed. the customers clearly want it, for example most programmers chose VS Code over a native app
I don't do much OS level engineering these days though and would probably fire up some VMs for that.
- Yes, these issues persist with WSL2.
- WSL2 allows mounting between the system/subsystem, but there is considerable overhead.
- Using WSL for remote workspaces from the host is very much a mixed bag.
- Attempting to use WSL entirely with graphical applications has very limited/poor support.
- If you wish for VM acceleration, you have to use Hyper-V, not all toolchains work with Hyper-V and this heavily restricts the host machine.
- If you wish to do anything that crosses the subsystem and the host, line delimiters and platform detection are very error prone.
- If you accidentally misconfigure WSL2 (which is quite easy to do) the WSL userspace can have substantial access to the host files, often beyond what may be initially apparent.
- Of compatibility issues, non-standard socket implementations have caused a lot of incompatibilities with software for me.
Considering it's just a headless linux vm with some integration with the host, I don't understand what reliability, performance or beyond it could possibly introduce beyond what any VM solution provides?
There are few gotchas with WSL. I hate how by default it includes your Windows path in your default linux path out of the box. It's easy to turn off and my init scripts for any VM always do that anyway, but it's the main thing I have seen people who are new to WSL get tripped by. It's useful to be able to run windows programs from within WSL. Like all the cli tools that pop up a browser to make you login, but that's about where its usefulness ends for me.
> No matter what you do, there will always be some weird platform detection
In my experience, unless you're running a very mainstream distro (read Ubuntu) there will always be a weird "platform detection" issue. I run openSUSE on most of my devices, and used to scripts not working because "uhhh, this is not Ubuntu or Debian or Fedora". The only time I run into "platform detection" issues are scripts that assume `uname -r` of a very narrow format.
> or line termination that pops up somewhere.
That goes back to my original comment about running Windows programs from linux, or moving files to/from linux. I never run into this issue because, just like on a linux desktop, I only interact with linux through the commandline. Even on a full linux desktop, I have this mental separation between GUI apps and terminal apps.
> it’s degraded performance or kernel-level incompatibility.
The only "kernel-level incompatibility" I run into is that WSL kernel doesn't have /dev/kvm. Granted I don't do a lot of kernel module specific development, so I don't know how something like a USB device or a PCIe interface can be passed to the WSL instance. But again, I'm thinking of it, and treating it like a user-mode development VM, not a full host.
I need it to access ssh keys from my yubikey. It’s painless if you just set it up to automatically forward the device on startup.
The only difference bettween 2010 and 2026, it that nowaday instead of having a mix of Virtual Box/VMWare Workstation depending on my work system, I have WSL 2.
However my Windows develoepr experience goes back to Windows 3.1, thus I mix and match my needs, between Windows and Linux sides.
WSL 2.0, and Virtualisation Framework are really the Year of Linux Desktop. /s
To which osigurdson seemed to be noting that WSL2 itself is a VM (meaning if you launch 1 or 100 WSL2 instances, a single Linux VM will be spun up), and when you run docker, it runs using exactly that same VM (optionally, though it's the default now to just use WSL2's backend).
Can you clarify what you meant by "A bit more overhead"? Running a container via docker or directly via WSL2 will use the same underlying VM, and there will only be that one VM regardless of the number of WSL2 or docker instances.
Once you start the second container the difference becomes more obvious: running $N containers in docker uses one VM with one linux kernel, no matter how many containers you add. Running $N containers as separate WSL instances runs $N VMs and $N linux kernels. That's the "bit more overhead" I was referring to
But it doesn't, and this is what I'm disagreeing with.
If you instantiate WSL2, it launches a Linux VM. A single Linux VM. If you then run Docker with WSL2 integration (the default and hugely recommended), it uses that Linux VM as its VM as well, so you're still at 1 VM.
If you run 100 WSL2 instances, they will all use that single Linux VM, each doing namespacing for isolation with their own filesystems. If you run 100 Docker instances, they will all use that single Linux VM.
If you run 100 WSL instances, and 100 Docker instances (assuming, again, WSL2 integration which is the default), they will all be using that single Linux VM.
Thus I begrudgingly use VSCode when forced to do so, otherwise I use the IDEs of each OS vendor.
It is these two operations at the heart of OP's app.
WSL2 distributions share the same Linux kernel. They only get their own root filesystem with a Linux userland (/bin, /usr, /lib etc), and some WSL config meta data. This is then stored as a virtual disk image (which is probably where your belief comes from). But the kernel runs in a single utility VM. The distros share that kernel instance and they are separated via namespaces only.
This makes running multiple WSL2 distributions in parallel very performant btw, as there is no world switch.
re: side-by-side running, I always get socket and/port port problems when doing that. Without having looked into it at all I figure it is NAT collisions.
WSL2 distros only use Linux namespaces, same as docker, and the WSL2 --system distro can see PIDs from all running WSL2 distros.
WSL2 has a single VM running as the process vmmem (or vmmemWSL in the newest versions). This is the single Linux kernel that will be shared by every WSL2 instance. It will also be the instance that hosts Docker containers as well. I mean, I'm just echoing myself and apologies for the repetition, but this is just easily confirmed, utter factual truth.
A rootfs is not a VM. WSL2 and containers have different nuances about their filesystem and isolation (WSL2 instances is aware of other instances, for instance, as a design aspect, and WSL2 persists rootfs changes while docker as a best practices does not), but they're more alike than different. And they share little in common with something like VirtualBox or vmware, which actually isolate every such system as VMs.
Again, sigh, if you install 10 WSL2 "distros", you will have 10 rootfs overlays on your drive, and 10 persistence VHD files. When you run these the VM they all run under in the shared vmmem instance, which is the single utility Linux VM.
https://learn.microsoft.com/en-us/windows/wsl/about
"WSL 2 uses virtualization technology to run a Linux kernel inside of a lightweight utility virtual machine (VM). Linux distributions run as isolated containers inside of the WSL 2 managed VM. Linux distributions running via WSL 2 will share the same network namespace, device tree (other than /dev/pts), CPU/Kernel/Memory/Swap, /init binary, but have their own PID namespace, Mount namespace, User namespace, Cgroup namespace, and init process."
(under "What is WSL2"?)
https://www.docker.com/blog/new-docker-desktop-wsl2-backend/
"WSL 2 runs all distros in the same utility VM, sharing the same Kernel."
If you run multiple distros take a look at the process manager and find the single vmmem or vmmemWSL (newer versions have the latter). That single instance is all of the instances, and all of the docker containers you might be running as well, each with namespace isolation (with WSL2 having intentional bridging between them for convenience). Visualise it by doing something intensive in any of them and seeing the single process react, because that's the single utility VM responsible for all of them. Further while starting up the first WSL2 instance or Docker container is expensive, requiring the initialisation of all of the resources for the utility VM and the memory to support it, subsequent iterations are much less expensive.
I wonder exactly how much work "container" is doing in that Microsoft blog post's description, because it doesn't seem like it's the same kind of environment as a runc or containerd container?
I also wasn't quite sure how much detail to infer from the behavior of vmmemWSL or vmcompute.exe, because my casual understanding is that there's some adaptation layer that handles mapping Linux calls to Windows calls. It seems reasonable to allow for process mapping or accounting shenanigans for any number of good reasons.
This was how WSL1 functioned. It used a shim layer, and honestly it was pretty neat for a lot of the basic stuff. It fell apart if you were doing more complex/advanced stuff, however, as there were many missing cases and exceptions.
WSL2 instead uses that utility VM, with a couple of special Microsoft kernel drivers to interact with the host system.