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Comment by lawl | Hacker News Reader

Thanks for the clarification. I at first assumed they'd bring OS level virtualization, apparently I'm not the only one. But it's basically just minimal images of windows in regular VMs then...

A step in the right direction but still disappointing imo. Linux and BSD are still miles ahead.

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So this is like boot2docker ... on Windows? You have a VM and you have containers inside it. This is not the same as containers on baremetal. But that is fine .. my confusion is the OS inside the VM. Is that Linux or Windows? Normally, I can run Ubuntu and Centos-based containers on my box. Can I run these as Hyper V containers? What about dot net? Can that be containerized.

No. When you talk about containers, you talk about operating system level virtualization[0]. This means you have one kernel, with multiple user spaces. You can run a CentOS container on Ubuntu because both use a Linux Kernel. What will actually happen is that CentOS will use your already booted Ubuntu Kernel.

So unless Windows switches to a Linux Kernel or vice versa you will never be able to run one as a container on the other.

You can however do that with Virtual Machines. But installing a stripped down version of windows in a virtual machine does not make it a container, it makes it marketing bullshit.

"Containers on baremetal" and containerizing dot net are thus a bit silly concepts since .NET has nothing to do with the operating system and you can't run a container on "bare metal" whatever you might mean by that.

[0] http://en.wikipedia.org/wiki/Operating-system-level_virtuali...

You might be able to run Windows containers under Wine....

That referrs to Nano, not Hyper V virtualization?

Microsoft is doing OS-level containers and they are also going to allow running containers in VMs.

Trying to clarify. We are talking about 3 things: 1) OS virtualization for Windows. We announced this last year: http://azure.microsoft.com/blog/2014/10/15/new-windows-serve... 2) Nano Server -- A small Windows Server sku. Perfect for containers, but also useful for other scenarios where you need a small, cloud optimized Windows 3) Hyper-V Containers -- Think if you wanted to optimize a hypervisor with assumption that it is only running a container. What enlightenments would you enable? What management interface would you put on it? We'll have more details later, but this is the core concept.

I guess the question is, are these containers a shared kernel, near zero overhead kinda thing? So I could just run, say, DNS or a file share in a container without paying any overhead. Like what containers/jails or OpenVZ can do on Linux.

In other words, if you want to run a Linux based Docker container on Windows you're still going to need Virtual Box.

> In other words, if you want to run a Linux based Docker container on Windows you're still going to need Virtual Box.

Is this a surprise?

Containerisation is not magical pixie dust -- it's a particular approach to implementation that is specific to the OS. You have a single kernel, and it follows that in general that single kernel will only allow corresponding containers to be run.

That there will be a Docker server backend that can speak Hyper-V doesn't magically make a Windows kernel into a Linux kernel, or vice versa.

You have a good understanding of why this is the case. Hyper-V would be doing the job of Virtual Box and boot2docker which is what most developers have been using to run Docker daemon on non-linux hosts. I've tried the Hyper-V driver with Docker Machine and had some issues. So I'll be sticking with Virtual Box until that changes.

Or Hyper-V, or VMWare Equivalent (Fusion/Workstation/etc)

They're doing OS-level virtualization in Linux Azure instances, sure. They don't seem committed to OS-level virtualization in Windows, unless I've missed something.

edit: http://research.microsoft.com/en-us/projects/drawbridge/ ?

That's what you would assume when you look at the image. But

> Hyper-V Containers, a new container deployment option with enhanced isolation powered by Hyper-V virtualization.

Everything written tells a different story. "Hyper-V virtualization" means virtual machines, making it not a container. They just try to make that sound like a feature.

Or do you have more information than I do?

All we have is a press release. The diagram and the constant references to containers would seem to indicate these are, well, containers. You're picking at a few things and assuming they mean that the rest of the release is wrong. Why?

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