WSL 2 is getting faster Windows file system access

(boxofcables.dev)

70 points | by haydenbarnes 6 hours ago

15 comments

  • asveikau 1 minute ago
    I was always disappointed with the design of wsl2. The wsl1 design of a syscall layer atop NT had greater architectural purity. They way I heard it, they introduced a virtual machine into the design specifically in order to bypass poor NT filesystem performance. I'm sure it's easier said than done, but it would have been nice if they instead fixed the issues on the NT side, rather than side step them with a VM.
  • avaer 1 hour ago
    Proton, Copilot, and literally this single issue are what pushed people to Linux. If I were in charge there would be a team devoted to fixing this a decade ago.

    WSL singlehandedly stemmed much of tide of developers moving away from Windows, but WSL native filesystem performance gave devs that magical experience when they boot into Linux the first time and see that the filesystem doesn't have to be ass. There's always been hacks around this, but for many devs the easiest hack was to ditch Windows.

    They should have moved heaven to fix this on day one, there's really no engineering excuse. Linux is open source.

  • phowat 1 hour ago
    Tangentially , I was a heavy used of wsl and moved to linux a few months ago and LLMs made most of the downsides of using linux as a desktop go away for me. I chatted with claude about the migration to find the best distro, decided on Fedora. After the install I asked everything I wanted to configured and got straight answers. In 3 or 4 hours I had an even more comfortable experience than I had on windows. AI made the annoying parts of trying to figure out how to edit all the config files to have linux behave the way you want very easy. I also had claude code write a bunch of scripts that I could have done but would probably never bring myself to actually do it . WHen you have a coding agent readily available , having an open source desktop environment makes a lot more sense. I encourage everyone to try it.
    • ragequittah 54 minutes ago
      I also did this as well as learned pfSense then OPNSense when pfSense went bad. Also made a pretty complicated XCP-ng setup. Learned all this with the ancient ChatGPT 3.5-4.0 models.

      I can hear a subset of people cringe saying "but LLMs are BS machines and you aren't learning anything!" I heartily disagree on both fronts. The main thing holding users like me back from linux was always the snarky RTFM community and the fact that everything has 25 different answers (depending on distro, window manager, and many other factors). LLMs take care of all this friction for you very nicely.

    • CamperBob2 9 minutes ago
      This. It is hard to exaggerate how easy Claude Code (or, I'm sure, any number of other harnesses of choice) makes it to migrate to a new operating system.

      It is truly a Star Trek-level experience. Nobody who doesn't want to run Windows (and who isn't forced to run it) needs to run Windows anymore.

    • hgoel 1 hour ago
      I did this too, made switching my desktop to Linux so much smoother. I have a Windows laptop for my Windows needs and most of my gaming is fine on the Steam Deck, so I realized I didn't need to always boot into Windows only to use WSL.
  • kenz0r 1 hour ago
    What killed WSL for me was the incredibly janky way I had to share USB peripherals. usb-ipd works 80% of the time, all the time.
  • thesis 2 hours ago
    Moved to mac about 7 years ago because of horrible WSL file system speed was.
    • nozzlegear 2 hours ago
      Same here, though I went to Linux first for several years. WSL file speeds, especially when running npm install, were the impetus that ultimately got me to switch off of Windows.
      • weird-eye-issue 2 hours ago
        Sounds like you were just doing it wrong

        Either you run npm install from Windows if you are operating on the Windows file system or you run it on WSL if you are operating on the WSL file system both cases will be very fast

        • lelandbatey 32 minutes ago
          Or, as they said, they didn't want to have to think about it so they chose to switch.
        • hparadiz 1 hour ago
          The entire Windows operating system is doing it wrong. Seriously who daily drives windows these days. lol.
          • thewebguyd 3 minutes ago
            Oh, you know, about 70+% of the global desktop/laptop market. Nearly every F500 company.

            But yeah sure, no one runs windows these days.

          • weird-eye-issue 1 hour ago
            Well before Windows I spent years with both Linux and Mac and I found Windows to be a good mix of stability and suitability for development now that WSL is a thing. Also for gaming it's the best by a long shot so just all around I've found it to be best and WSL made me never miss Linux.
            • hparadiz 1 hour ago
              Nah my frames on Linux beat yours easily.
              • weird-eye-issue 1 hour ago
                Unlikely due to the better and more stable NVIDIA drivers available to Windows and the greater compatibility with every game without having to mess around with configuration files or other hacks. But you do you.
                • lmm 1 hour ago
                  > better and more stable NVIDIA drivers available to Windows

                  Huh? It's the same driver. It works the same on every platform. There's no consistent difference in performance (at least not between FreeBSD and Windows, it's been a while since I ran Linux).

                • hparadiz 1 hour ago
                  Linux drivers are now first class and are faster and easier to install than any Windows drivers. There's no bullshit extras with them. They just work. Plus steam launches games in containers so there's zero configuration. If you don't know what you're talking about it is in fact better to say nothing than to just make shit up.
                  • weird-eye-issue 1 hour ago
                    It's great that gaming on Linux has gotten a lot better over the last several years but let's not pretend like Windows still isn't far ahead on this

                    Also how can drivers be easier to install than on Windows when updating my GPU driver is one click?

                    • hparadiz 1 hour ago
                      Here's a pre-configured Fedora based distro that is zero clicks. You sign into Steam and go. Drivers are preinstalled. You literally sign into steam and hit play.

                      https://nobaraproject.org/

          • flaunf221 1 hour ago
            I do and I have no problems. Feel free to ask me anything.
    • weird-eye-issue 2 hours ago
      You could just move your files to the WSL file system
      • hparadiz 2 hours ago
        That kind of defeats the entire purpose of them being accessible from the rest of the system.
        • weird-eye-issue 1 hour ago
          You can access them from the rest of the system. For normal usage the performance is completely acceptable but for development tasks it matters.
          • hparadiz 1 hour ago
            > Just copy it into the WSL file system

            Yea bro totally. Totally. I'm gonna copy 2TB of media into the WSL virtual disk just so ffmpeg can run a little faster but still way slower than simply running linux.

            (I beta tested the shit out of WSL1 and 2) before I wised up and just installed Gentoo forever.

            • weird-eye-issue 1 hour ago
              You can run that directly on Windows.

              But either way yeah most people aren't dealing with large media libraries that's obviously a little more difficult. But if you are primarily operating on them with WSL then you would just keep them in the WSL file system and you could access them from Windows whenever you need to...

  • avadodin 3 hours ago
    If it is as good of an improvement as the first major update, it will be hard to tell from native.

    Hopefully, they will just push it out to everyone asap. We make heavy use of symlinks into Windows drives.

  • cmovq 25 minutes ago
    I had no idea they used the Plan 9 file server for accessing files in WSL. I wonder what the original reasoning for choosing 9P was.
  • chris_money202 2 hours ago
    They are undoubtly doing this because so many users operate out of /mnt/c with zero clue of that implication.
    • alberth 2 hours ago
      Would you mind elaborating (for those of us uninformed)
      • omcnoe 1 hour ago
        /mnt/c is a mounted C: drive in WSL2, that allows WSL2 guests to read/write files on the Windows host.

        The mount is fine and speedy enough, but the underlying reads/writes turn into native NTFS reads/writes through Windows. NTFS file API is incredibly slow - high fixed overhead for initial file access.

        So patterns like node_modules with many small individual files (or compiling code in general) are much much slower on Windows or WSL2 /mnt/c due to the fixed overhead adding up over a large number of files.

        It's a ridiculous problem that has plagued Windows for years.

      • weird-eye-issue 2 hours ago
        One example is that if you have a node modules folder on Windows and you try to delete it from WSL it can take 10 plus minutes whereas if you deleted it directly in Windows it would have just taken a few seconds

        Also if you try running Next js from files on Windows from WSL it takes minutes for each page to compile to the point that any local development is impossible so you would have to either run the Next JS server on Windows or move the files to WSL

      • yakz 2 hours ago
        It's difficult to overstate how horrible the performance is.
      • tonymet 2 hours ago
        WSL2 is a VM based on a Windows virtual disk file (VHD). inside that VHD IO is quite fast , a couple degrees worse than native. /mnt/c is how you access your windows files, but it's slow like NFS (socket based). anything needing high IOPS will be dog slow e.g. compiles, file scanning, etc.

        the rule of thumb without the newest features is to copy work to/from /mnt/c into $HOME as needed.

  • themeiguoren 3 hours ago
    I can’t find any benchmarks on this, anyone have a sense of the speedup that can be expected here?

    And for what it’s worth, that version isn’t available yet when I try to update WSL.

    • tonymet 1 hour ago
      more or less this is what I ran to benchmark

      https://gist.github.com/tonymet/ec7fc4af0eb11c9d5af22c76d056...

    • tonymet 1 hour ago
      wsl version 2.7.7 seemed to work with the listed config + reboot
    • tonymet 1 hour ago
      a test compile of hugo (moderate go app) on a AMD Ryzen 7 7735HS with SSD

      WSL filesystem = 50s

      virtiofs = 75s

      it seems a lot faster. I don't use drvfs (windows files) usually. 50% performance gap is good.

      And MS Defender kicked in beforehand losing about 10 seconds. with some config you could turn off defender and get this down to 60s

  • zaptheimpaler 1 hour ago
    I was trying WSL years ago and this is one of the reasons I just moved to a full linux server instead. We still have way too many problems interfacing across filesystems. I hope with AI we will see an iteration on ExFAT that has all the journalling, versioning etc. magic of modern FS' and can be adopted across all 3 OSes. Probably a long shot but I can dream :)
  • agentultra 40 minutes ago
    Do the audio buffers to the host device next!
  • sanp 1 hour ago
    Hasn’t this always been the case? I have always run builds under WSL2 in Windows because of this.
    • tonymet 57 minutes ago
      when you mount "drvfs" (the automounting feature, or you can call mount -t drvfs) , it's usually plan9, which is like NFS.

      with the new wsl version, kernel and config from that blog, it will mount virtiofs, or warn you

  • mattkevan 1 hour ago
    Where are we on the embrace/extend/extinguish curve right about now?
    • protocolture 1 hour ago
      Microsoft is almost done extinguishing Windows.
  • phendrenad2 1 hour ago
    Hopefully they're heading towards a "boot to Linux" mode.
  • tonymet 1 hour ago
    counterpoint: WSL is great. I like it. I enjoy & prefer Windows desktop & Linux terminal. very happy.