back to article Microsoft unshackles WSL2 Linux kernel from Windows 10 image for future fettling via Windows Update

Microsoft has broken its long-running record of tedium with Windows 10 Insider builds by shunting the newly added Linux kernel into Windows Update. First mooted back in March by program manager Craig Loewen, the change removes the Linux kernel from the Windows Image and instead flings it at Windows Update. The shift means that …

  1. Hans 1

    Junction support

    Sluggish IO performance when accessing Windows files is a bit of a bummer, though ... does it support NTFS junctions ? I assume the vhdx is mounted in Windows, somewhere ...

    Why instruct to do cd ~ when cd is sufficient ?

    1. katrinab Silver badge
      Meh

      Re: Junction support

      I'm guessing, as it is basically an optimised Hyper-V image, you access windows volumes via Samba?

      1. Dan 55 Silver badge

        Re: Junction support

        Yes, you also can't set DISPLAY to localhost:0 because it's in a VM.

        I installed it against my better instincts but at least the computer didn't go up in flames, that's 'pretty good' when it comes to major Windows version upgrades.

      2. Nano nano

        Re: Junction support

        I may have misunderstood, but when I used WSL, you mounted Windows D, E etc drives at a Linux mount point.

    2. Androgynous Cow Herd

      Re: Junction support

      I read that as "SAMBA continues to suck".

  2. Anonymous Coward
    Anonymous Coward

    I love that linux updates apply in about 15 seconds, in the background, without requiring a reboot. Windows updates take half an hour of constant disk churning, several reboots, and sat looking at a 'windows is applying updates.. do not turn off your computer' screen

    1. Steve Davies 3 Silver badge

      re: speedy Linux updates

      I'm sure that there is a team in Redmond (or India) working away 24/7 to put a stop to that. MS can't let those FOSS boys get one over on Microsoft. It does not look good when their process sucks so much and has done for years and despite countless thousands (if not more) people telling them to sort it out. But, they don't.

      1. A.P. Veening Silver badge

        Re: re: speedy Linux updates

        Don't worry, they'll bork the Linux update any day now.

        1. julian.smith
          WTF?

          Re: re: speedy Linux updates

          They won't bork my Linux update .... I don't use malware posing as an error riddled OS

    2. julian.smith
      Linux

      re: speedy Linux updates

      I enjoy it that Linux (Mint) updates quickly and doesn't require a reboot.

      Updates also don't bork the OS.

      What is this "Windows" of which you speak?

      LMAO

      1. Wayland

        Re: re: speedy Linux updates

        Windows 10 is very similar to Linux Mint but you'd need a jolly good reason to switch to it. It's constantly in BETA and requiring massive time consuming updates that are apt to arrive at the wrong time or if you've not used your computer for 3 days. The updates themselves are hard to manage and could mean you need to re-install your entire system.

        If you feel you are technically competent to live with these problems you will be rewarded with very good compatibility with earlier Windows programs going right back to the start of Windows. There is also a thriving games market on this platform but most of those games work just as well on Windows 7.

        I would not recommend Windows 10 to your nan or mother or anyone not competent with computers. Hopefully one day Windows 10 will leave BETA and be ready for general commercial use. It does look promising and could one day be a really top notch OS. Fingers crossed.

    3. damiandixon

      Just saying... Kernel updates require a reboot.

      1. Hans 1
        Boffin

        Look again

        1. Hans 1
          Facepalm

          Downvoter: Look harder! You can update the kernel without restarting with livepatch.

    4. Wayland

      Just turn the computer off. Half the time it's fine. The other half of the time you have to reformat and start again.

  3. Anonymous Coward
    Anonymous Coward

    It's not an OS

    Please stop referring to Windows 10 as an Operating System.

    It's not an OS, it's just an optimized game playing environment that lets you email occasionally. Linux is a real Operating System and they are just thinking that they might add a real OS to Windows 10 ... but they will screw it up because they will want to make it work with an Xbox.

    1. bazza Silver badge

      Re: It's not an OS

      Hmm well, I think you'll find that the ancestors of modern day Windows (which can include VAX / VMS if you really want to be pedantic about it) were doing fine work years before Linus stopped wearing short trousers.

      Also, a point of terminology. Linux is an operating system kernel, not an operating system. RedHat, Ubuntu, are operating systems.

      1. dharmOS

        Re: It's not an OS

        Dave Cutler was lead on VMS/VAX when at DEC, lead on Win NT kernel after moving to MS, and now leads development on the hypervisor on Xbox One.

        https://en.m.wikipedia.org/wiki/Dave_Cutler

        Fanboy comments about Linux (or OS/2 etc, which I was a zealot for in former days) are just that.

        1. bazza Silver badge

          Re: It's not an OS

          Ah, OS/2. Fond memories. Some of the ideas in the desktop were really good and still are. Pity that some of IBM's design decisions basically condemned it. On balance MS were right to walk away from it and do NT.

          1. bigmacbear

            Re: It's not an OS

            My dev team back in the day used OS/2 to allow for multiple DOS windows running concurrently to manipulate specific hardware devices (nowadays those would be VMs with dedicated drivers for the physical devices). We jokingly pronounced OS/2 as "OS over 2" i.e. half an operating system.

          2. Wayland

            Re: It's not an OS

            OS/2 was very smooth for running multiple DOS windows doing various hardware related things.

          3. Nano nano

            Re: It's not an OS

            Such as a single system event queue ...

      2. martinusher Silver badge

        Re: It's not an OS

        Realistically you can't have two kernels running on one processor (a hypervisor is just a subkernel that runs the virtual OS kernels as tasks under it). So what is it?

        Is it a Windows kernel running a Linux emulation (Cygwin on steroids) or a Linux kernel running Windows OS services (Wine on steroids). If the answer is 'both' then its likely that what is really running is 'a mess'.

        The only reason for running Windows is the proprietary applications environment that runs on top of it. Its embedded in business, generations of IT support staff are drilled in its Voodoo and so on. It is a bit unwieldy to use outside of this ecosystem -- you don't have to be a Linux fanboi to know this -- and as its a bit of an architectural dog's breakfast I'd guess -- maybe even hope -- that Microsoft has seen the light and is moving steadily towards taking the step Apple did years ago with OSX. That is, putting all their proprietary stuff on top of a properly designed kernel where it keeps business happy and allows the rest of us to get on with useful work.

        (As for VMS and so on -- some years ago in the NT world Microsoft had a POSIX compliant kernel down there that was actually really useful. For a brief moment in time there was an actual OS down there. That got superseded buy Heaven only knows what. Meanwhile we're saddled with an arcane filesystem that still thinks that physical devices are relevant to the filesystem structure (kludged up, of course, but those floppies and the hard drive are still there....), a pathname structure that's incompatible with the rest of the world and a device driver structure that are for the most part 'amusing'. What's not to like?)

        1. katrinab Silver badge

          Re: It's not an OS

          WSL1 is like Wine in reverse, so the GNU operating system isn't actually running on Linux. Unlike Cygwin, it allows you to run native Linux binaries, so you don't have to recompile everything. FreeBSD and a few other operating systems have something similar.

          WSL2 is an optimised Hyper-V image, so does come with an actual Linux kernel.

        2. bazza Silver badge

          Re: It's not an OS

          I think @martinusher needs to read some of Alan Turing's papers. You seem to be failing to understand the fundamentals of computing. Any Turing complete machine can emulate any other Turing complete machine, given enough memory. This, fundamentally, is the reason why emulation and virtualisation works. So any computer made at any point in the past 70 years or so can, with enough memory, emulate any of today's machines, the software running on them and produce the same outputs. Though you might have to wait a while for some of them to do so... Modern CPUs from Intel and AMD just happen to provide hardware support for efficiently doing this for x86/x64 machines.

          It's also the reason why a modern CPU from Intel and AMD can still run x64 / x86 opcodes. They're "emulating" an x64 or x86; their execution units in their cores don't actually have a scoobies how to run those opcodes, they have to be translated first.

          What on earth do you mean by "POSIX compliant kernel"? There's no such thing. POSIX merely mandates that certain APIs are implemented, and certain tools provided. The whole point of POSIX is to isolate developers from the underlying kernel. Any kernel ever written is, given enough memory, capable of supporting those APIs (though again, you may have to wait a while). There is nothing magical about the Linux system calling interface that makes it "POSIX", in the same way there's nothing magical about any kernel commonly found in any unix-like OS that makes them "POSIX" either.

          And there's nothing about the NT kernel that precludes a POSIX environment being plonked on top of it either. As you point out MS has had several goes at this, the most recent being WSL v1 which did it by implementing the Linux system call interface enabling the POSIX environment provided by glibc and the various utilities packaged up into a distro by Ubuntu to run without recompiling.

          Also, Windows is generally quite happy these days with '/' as a path separator. Though to be pedantic about it, the representation on our screens of the byte sequence which, in a path string, is generally taken to mean "path separator" is purely arbitrary. You like '/'. Microsoft chose '\' and is happy with '/' too. Japan is quite happy using '¥', as a result of early computers being stuck with 8 bit code pages and there not being enough room to accommodate both '\' and '¥' at the same time. All that matters is that, somewhere down the API / kernel stack, there's agreement as to what to expect in a path string.

          Also your suggestion that the Windows kernel is improperly designed is entirely subjective. There's many clever aspects to the current kernel, and it has some security tricks that Linux doesn't have. That's not to denigrate Linux - it's just different design choices.

          However, what is possibly going to happen in the next few years is that Microsoft will start reimplementing bits of Windows kernel using Rust instead of C. That would be a very smart thing to do as this, thanks to the syntactical ideas in the Rust language and the maturity of the compiler, makes it very easy to not screw up memory usage. That, for a team implementing a kernel, is a very useful trait.

          If Windows starts heading down the Rust road, and Linux doesn't, this will eventually show up in a clear demarcation between the two (and indeed any other OS using Rust, which may include Google's Fuchsia and Redox (brand new)), in that Windows' kernel would end up being devoid of memory based vulnerabilities, assured automatically by the Rust compiler, whilst Linux won't. I doubt that this will particularly affect which one gets used by end users, but Rust is clearly the modern way to go, and it'll be hard to get exploits on Windows. As for systemd, being written in C - that is probably going to cost dearly in years to come (arguably it already is).

          1. Dan 55 Silver badge
            1. Wayland

              Re: It's not an OS

              Memory allocation and pointers is what makes C programs crash.

              I remember writing embedded C code that ran on hardware with no OS. The C compiler had no malloc() or memory allocation.The programs were so much more reliable than anything written in C for the PC. No memory leaks.

              If RUST makes sure you can't make those memory mistakes then operating systems will become far more reliable.

              1. Dan 55 Silver badge

                Re: It's not an OS

                malloc() is really a function belonging to libc, not the OS. There are libcs which are more suitable for embedded use.

                All problems with allocation and pointers are down to the programmer. Methodologies like RAII can help avoid them even in C.

                As you can see from the link, Servo had a double-free problem even with Rust.

        3. Anonymous Coward
          Anonymous Coward

          @martinusher - Re: It's not an OS

          Our work is useful only if it keeps business happy! Don't take my word on it, put it to the test yourself.

          And in case you might miss it, it was not the POSIX compliant kernel but the awful things you describe that helped Microsoft climb to the top of an insanely high mountain of cash. It's sh$%t but highly profitable so why walk away from it ?

          1. bazza Silver badge

            Re: @martinusher - It's not an OS

            It's sh$%t but highly profitable so why walk away from it ?

            That's a subjective opinion. However, if the enormous pile of money that continues to be amassed by MS is anything to go by, an awful lot of people have continually disagreed with you for many years even after MS were stopped from imposing anti-competitive license conditions on hardware vendors.

            1. Anonymous Coward
              Anonymous Coward

              @bazza - Re: @martinusher - It's not an OS

              Did Microsoft really stopped doing that to PC vendors ? Are you sure ? Last time I checked, there is not even a single one who would sell you a PC without OS (what we used to call a naked PC). Not even at a higher price than one that comes with Windows (some of them will sell you a few lower end models with FreeDOS preinstalled). Also, when you buy a Windows PC, looking at the price tag, what is the cost of hardware and what is the cost of the OS ? Why aren't you given the option to say "I'll take the hardware only, thank you very much" ? I'm not that much a MS hater but still, let's not ignore facts.

              1. CRConrad

                Yes, they'll sell you PCs without OSes.

                An AC writes:

                Last time I checked, there is not even a single one who would sell you a PC without OS (what we used to call a naked PC).
                https://system76.com/

                https://support.lenovo.com/fi/en/solutions/pd031426

                OK, so those have Linux on them; you may be paying some for (the install of) that.

                So check this: https://bestware.com/en/schenker-slim-14.html . Click on “Configurator”, then scroll down almost to the bottom: the “Operating System” selection is like fourth-last.

                1. dajames

                  Re: Yes, they'll sell you PCs without OSes.

                  https://support.lenovo.com/fi/en/solutions/pd031426

                  That says that certain Lenovo models are "Certified for Linux". I have one of the machines listed, and I do run Linux on it, but I was unable to find any way to buy it without Windows preinstalled.

                  Maybe if I'd been a big corporation wanting several hundred machines with the same OS they'd have been prepared to oblige, but buying online from Lenovo UK there was no option for either a bare machine or for any non-Windows OS.

                  Yes, you can get some PCs without Windows -- Dell do some, for example -- but not everyone makes it easy.

                2. TonyJ

                  Re: Yes, they'll sell you PCs without OSes.

                  Mentioned it before but PC Specialist will also sell a PC or laptop without a Windows OS. True, it will ship with an unactivated copy of WIndows 10 that they use for burn-in testing and they don't actively support Linux but you can buy the machine sans license.

              2. Jedipadawan

                Re: @bazza - @martinusher - It's not an OS

                For what it's worth, I have purchased a number of laptops here with EndlessOS pre-installed. It is illegal to sell a new laptop here but vendors at the local 'Hi-tec Mall' had provided laptops with FreeDOS allowing for a machine without the Microsoft tax.

                Having said that, the Hi-Tec Mall is being whittled away and my experiences of buying online have been...poor. In Indonesia you MUST inspect and test before purchase or buy from someone of absolute stirling repute!

              3. damiandixon

                Re: @bazza - @martinusher - It's not an OS

                You missed the announcement from Lenovo about first line support for Linux preinstalled with upstreaming of all of the drivers.

              4. Nicodemus's Knob
                Thumb Up

                Re: @bazza - @martinusher - It's not an OS

                You've been able to buy PCs from Novatech without an O.S. for years. https://www.novatech.co.uk/workstation/graphics/

        4. IGnatius T Foobar !

          Re: It's not an OS

          As for VMS and so on -- some years ago in the NT world Microsoft had a POSIX compliant kernel down there that was actually really useful. For a brief moment in time there was an actual OS down there. That got superseded buy Heaven only knows what.

          In the original version of Windows NT, the Win32 subsystem was one of three (Win32, OS/2, and POSIX) that sat on top of a microkernel. But then Microsoft went and loaded all of their bloat into the Win32 layer instead of continuing the proper microkernel architecture.

          This is ironic considering they should have learned from their mistake of bloating Win16 on top of MS-DOS.

    2. Tom 38

      Re: It's not an OS

      It's not an OS, it's just an optimized game playing environment that lets you email occasionally.

      Even if it was just that, that is an Operating System. What runs on an Xbox is an OS. Tedious fanboyism is tedious.

      1. Doctor Syntax Silver badge
        Linux

        Re: It's not an OS

        "Tedious fanboyism is tedious."

        Not so much tedious as ill-informed.

      2. Wayland

        Re: It's not an OS

        I think you're being pedantic. The point he is making is that running an OS is not the purpose of a computer but the main reason for choosing Windows 10 is it's quite a good games platform but not much good for anything else.

        Gamers really don't care what's actually on their computers because they can easily wipe it and start again. Their game accounts remain online. If Valve ever made a completely game compatible OS gamers would simply Wipe Windows next time it broke and install SteamOS.

  4. Anonymous Coward
    Anonymous Coward

    Wondering about GPL requirements....

    So.....once I've clicked through the M$ EULA, does WSL1 (or WSL2) comply with the linux kernel GPL requirements? Is there any other open source code in there which needs to comply with other open source licenses (BSD, MIT, Apache.....you know, the usual suspects)?

    1. Roland6 Silver badge

      Re: Wondering about GPL requirements....

      Thats (GPL et al licensing incompatibility with MS license) probably a reason why MS are no longer shipping WSL2 as an integrated component in the Windows distribution.

  5. IGnatius T Foobar !

    How about more separation?

    Good first step ... now let's see Microsoft allow Windows users to uninstall Edge, Cortana, and the dozen or so other components that are NOT baked into the kernel but prohibited from uninstall anyway.

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