WSL 2 Post BUILD FAQ

Craig Loewen

Craig

After announcing WSL 2 last week, we have had an amazing response from the community and received many great questions about the details surrounding this new architecture. We love answering your questions and want to make sure these answers reach as many WSL users as possible. In this Q&A styled post we’ve gathered some of the most frequently asked questions, and our responses.

Does WSL 2 use Hyper-V? Will it be available on Windows 10 Home?

WSL 2 will be available on all SKUs where WSL is currently available, including Windows 10 Home.

The newest version of WSL uses Hyper-V architecture to enable its virtualization. This architecture will be available in an optional component that is a subset of the Hyper-V feature. This optional component will be available on all SKUs. You can expect to see more details about this experience soon as we get closer to the WSL 2 release.

What will happen to WSL 1? Will it be abandoned?

We currently have no plans to deprecate WSL 1. You can run WSL 1 and WSL 2 distros side by side, and can upgrade and downgrade any distro at any time. Adding WSL 2 as a new architecture presents a better platform for the WSL team to deliver features that make WSL an amazing way to run a Linux environment in Windows.

Will I be able to run WSL 2 and other 3rd party virtualization tools such as VMware, or Virtual Box?

Some 3rd party applications cannot work when Hyper-V is in use, which means they will not be able to run when WSL 2 is enabled. Unfortunately, this does include VMware, and versions of Virtual Box before Virtual Box 6 (Virtual Box 6.0.0 released in December 2018 now supports Hyper-V as a fallback execution core on a Windows host!)

We are investigating ways to help resolve this issue. For example, we expose a set of APIs called Hypervisor Platform that third-party virtualization providers can use to make their software compatible with Hyper-V’s. This lets applications use the Hyper-V architecture for their emulation such as the Google Android Emulator, and Virtual Box 6 and above which are both now compatible with Hyper-V.

Can I access the GPU in WSL 2? Are there plans to increase hardware support?

In initial releases of WSL 2 hardware access support will be limited, e.g: you will be unable to access the GPU, serial or USBs . However, adding better device support is high on our backlog, as this opens many more use cases for developers that wish to interact with these devices. In the meantime, you can always use WSL 1 which has serial port and USB access. Please stay tuned to this blog and WSL team members on Twitter to stay informed about the latest features coming to insider builds and reach out to give us feedback on what devices you’d like to interact with!

Will WSL 2 be able to use networking applications?

Yes, in general networking applications will be faster and work better since we have full system call compatibility. However, the new architecture uses virtualized networking components. This means that in initial preview builds WSL 2 will behave more similarly to a virtual machine, e.g: WSL 2 will have a different IP address than the host machine. We are committed to making WSL 2 feel the same as WSL 1, and that includes improving our networking story. We expect to add improvements as quickly as we are able to, such as accessing all networking apps from Linux or Windows using localhost. We will be posting more details about our networking story and improvements as we approach the release of WSL 2.

If you have further questions about WSL, or simply want to reach out to the team you can find us on Twitter!

WSL Team members on twitter:

  • Taylor Brown @Taylorb_msft
  • Yosef Durr @yosefdurr
  • Sven Groot @svengroot_ms
  • Ben Hillis @benhillis
  • Craig Loewen @craigaloewen
  • Sunil Muthuswamy @SunilMut
  • Brian Perkins
  • Palkesh Soni @sonipalkesh
  • John Starks @gigastarks
  • Craig Wilhite @CraigWilhite
Craig Loewen
Craig Loewen

Program Manager, Windows Developer Platform

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15 Comments
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Hristo Hristov 2019-05-13 21:00:15
I really hope for GPU support, specifically Vulkan, eventually OpenGL. Currently I think HyperV supports GPU pass-through which requires BIOS support and hardware support (Quadros). I hope for some sort of VirtualGPU that uses the Windows drivers. Threre are a few reasons I don't want to boot Linux and work in a virtualized environment and the main are laptops, Optimus and poor power management and drivers under Linux for laotops.
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Ian Yates 2019-05-13 21:34:16
I'd like to understand more about the file system access.  WSL 1 stored the files in a folder in app_data. Does WSL 2 do this? I'd guess yes since you talk about up & down grade at any time. Wondering if you could confirm this please?  Thanks 
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Manuel Bernhardt 2019-05-13 23:13:15
First i thought: Wow! Full linux support with WSL? Make me happy as developer! But now i read in your faq, you are using hyper-v which means for me/us, i can not longer use my virtualbox VM for developing. That was the reason, i don't use docker for windows and yes, it would it also make hard for me, switch to WSL2. Please support virtualbox and vmware asap with a api, made they running.  Thank you in advance!
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TN 2019-05-14 00:35:55
What about filesystem access?
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TN 2019-05-14 00:39:59
Could someone compare WSL2 vs. Linux virtual machine in HyperV.
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Moritz Beutel 2019-05-14 06:53:09
Any chance that the SLAT/EPT requirement could be lifted for the Hyper-V subset you rely on, so it would work on older CPUs without SLAT? It is good to know that WSL 1 is not considered deprecated (though I wish you had chosen a different name for "WSL 2"); but does this mean that you will keep extending the syscall coverage of WSL 1, or is WSL 1 considered "done"?
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Daniel McPhail 2019-05-14 18:01:13
Will there be a way to choose a different install location for WSL 2 and it's programs? For example, my computer doesn't have a lot of space on it's main drive so I'd like to keep WSL 2 and all of it's stuff on a separate hard drive so it doesn't interfere with my normal usage of my computer.
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Stéphane BARIZIEN 2019-05-15 06:55:30
I encourage everyone to view the recording of the "The new Windows subsystem for Linux architecture: a deep dive" //Build 2019 session BRK3068
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Galih Gusti Priatna 2019-05-15 08:12:28
How about ext4, ext3, and ext2 filesystem? Are it supported on WSL 2?
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Alexis Ryan 2019-05-15 14:47:11
Will it still be possible to pipe input andoutput between winows and linux processes in wsl2 or will i want to stay with wsl1 for that
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Tim Wood 2019-05-15 20:20:33
I think I know the answer to this already.... Can I run Windows 10 with WSL 2 as a guest in a virtual machine?  I would expect no, as that would seem to nest VM monitors/hypervisors.
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沐雨 林 2019-05-17 09:49:44
I want to know about the  optional component that is a subset of the Hyper-V feature is this work as vmware or other vms(only open when I use wsl2 and hyper-v disapper when I close wsl2) . I use wsl1 because I don't want my win10 turn to a guest os of hyper-v Hypervisor