Hacker News Reader

Comment by mullingitover | Hacker News Reader

This is still with Linux running in a VM though, right? I'd like a lightweight VM for legacy Windows and Linux running on metal.

Given Microsoft's zeal for legacy support I'd say there's a snowball's chance in hell for this, but a man can dream.

View on HN

When you run a type-1 hypervisor, the only thing running on the metal is the hypervisor.

This is what happens in the case of WSL 2; both Linux and Windows (the host OS) run in very (very) lightweight VMs.

Iirc, even the Win32 APIs sit above the subsystem layer. There was the OS/2 subsystem back in the day, Win32, and one more I can’t remember from my training 11 years ago.

posix subsystem?

I think that was newer than my training. This was the Vista timeframe.

The posix subsystem was a thing even when xp was around

Just run Linux and then run a Windows VM in QEMU, seems like you can do this now.

I just want Linux with the ability to use PowerPoint.

(I also want to just be about to plug in my HDMI to my laptop and have it work. Literally the only two things I care about)

FWIW, I have given major conference talks years back on my linux laptop with PowerPoint running via Crossover Office (wine), mostly due to my advisor's insistence on using PowerPoint. So that has already been a thing for a long while.

My issue is that with nvidia laptops the hdmi connection almost never works as expected, when I have cuda installed. I'll try proprietary or noveau drivers. I've driven my monitor with intel drivers. I've tried so many things, but it has been multiple laptops that I've just never gotten this to work. I just can't have cuda and use my laptop for presentations. So I just always keep a windows partition just for presentations. If you do have a suggestion I'd love to hear it.

I've never used crossover. Thanks, I'll look into it.

I tried to do CUDA programming on a laptop with Ubunto but gave up. It worked fine on a stationary computer.

There has to be something with Cuda that messes everything up on laptops.

I would actually wonder if it could do that via VMs. That why you can keep compatibility, but then change the underlying system.

WSL version 2 uses the Hyper-V Virtualization API but is not a VM.

The first version of WSL is just another process in task manager, with all the syscalls and filesystems emulated.

Well, each WSL1 process is a Windows process. If you’re running vim in bash, for example, you’ll see “vim” and “bash” as separate processes in Task Manager. WSL is all about ELF binaries natively, just as Win32 runs PE executables natively.

"windows process" is misleading, WSL uses a separate "linux subsystem" with its own syscalls, process/thread data structures, etc. It also uses its own file system (albeit with all the state stored in NTFS and affected by filter drivers, which is why its I/O is slow)

They are Windows processes, just as the Win32 subsystem also spawns Windows processes.

Probably best to refer to them as NT processes for the sake of clarity.

True, I thought that a few hours after I wrote my last comment but couldn’t update it by that point and didn’t respond to it. Windows NT is the kernel, Win32 is the Windows subsystem that everyone’s used to (including kernel32.dll), WSL is a subsystem that runs ELF binaries and implements the Linux syscalls. It’s not yet obvious to me how much WSL2 is actually even a Windows subsystem, given that it’s running it as an actually separate OS.

I dont think its a VM like Docker no. WSL processes show up under the task manager. This is more like Wine but Line... In a sense. But a little trickier.

Docker's not a VM.

Someone who uses MacOS might think Docker implies a VM perhaps? (Linux VM needed to get Linux Containers to run).

Do Docker people really think it’s a VM? Or has the meaning of “VM” shifted this past year?

I think the OP is probably referring to the fact that running Docker on Windows and macOS is accomplished by running a Linux VM which the Docker containers run in. Not that Docker containers are VMs.

I didn't know that macOS users don't run Docker natively! On Windows, it's native:

https://docs.docker.com/docker-for-windows/

In practice, the vast majority of docker containers are Linux containers, so most uses of docker for windows need a Linux kernel to do anything useful.

As such, the 'native' docker for windows you linked is actually managing a Linux VM (HyperV or VBox) fot you; the docker server runs on that VM, and the native docker windows binary simply connects to that server.

They also do a lot of tricks to connect networking and file shares with that VM. The file shares part is almost completely non-working in my experience, with scary comments in the bugs like 'doesn't work if your windows password contains certain characters' (it sets up CIFS shares between the Linux VM and some parts of your Windows file system).

So, not sure what docker for Mac looks like, but Docker For Windows is only 'native' in a very hand-wavy sort of way, unless (maybe) if you're running Windows docker containers.

docker for mac uses xhyve/hyperkit and has a really really slow i/o.

That cannot run Linux containers, only Windows containers, no?

You can switch between one or the other. Oddly, it can't run both at the same time.

Yes. If you're running Windows containers you can be "native" docker.

However, we use VMs managed with Salt for our Centos VMs. I never saw the need for Docker. Maybe if I did "web" stuff.

Docker desktop runs a Hyper-V VM. Prior to that, Docker used a Virtualbox VM on Windows. The current plan seems to be to integrate with WSL2 once that ships [1].

[1] https://engineering.docker.com/2019/06/docker-hearts-wsl-2/

This is what I meant by this. Most people I know using Docker are not on Linux but on Mac and Windows.

Reply on news.ycombinator.com