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Comment by paulmd | Hacker News Reader

The BSD world has had this for ages in the form of "branded zones" in opensolaris/illumos and linuxulator for jails.

It's too complex to thunk windows calls to linux, that is what WSL1 tried and failed at, because windows is just too different from a POSIX paradigm for that to work well. But posix-on-posix isn't really all that hard... nor is other *nix-on*nix.

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> that is what WSL1 tried and failed at

What did they do differently with WSL2+?

Everything, WSL2 is a special hyperv vm. It’s a true Linux kernel with a true Linux file system. The network stack is one way integrated so you don’t have to forward any ports or configure NAT.

Broadly speaking WSL1 is linux implemented in the windows kernel, think reverse wine. WSL2 is linux running on a thin VM with several bridge layers that can access windows resources (networking, files, GPU, etc.)

Thanks for the explanation! I always knew that WSL1 was implemented on the Windows kernel and thought it was quite ambitious - props to them! I didn't know they moved to the VM model for WSL2.

Isn't WSL1 everything _but_ linux? I.e. more like gnu/WinNT.

WSL2 uses VM. So actual Ubuntu distribution under the hood

It runs a hyper-v VM with a Linux kernel.

I wonder if Windows could add more support in the kernel for better POSIX support, or maybe it's just too hard.

They tried, it was possible but way too slow to be usable due to all the baggage that the NT kernel carries (think antivirus support).

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