Microsoft releases Windows Subsystem for Linux 2.0.0 with fixes and experimental new features

Microsoft's love for Linux shows no signs of waning, with the company releasing an update-packed pre-release build of WSL 2.0.0.

There are many changes in Windows Subsystem for Linux 2.0.0, and as this is a pre-release version it’s perhaps to be expected that many of the new additions are described as "experimental". One of the biggest new features is experimental.autoMemoryReclaim which shrinks the WSL VM in memory by reclaiming cached memory.

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There are new networking features to experiment with, including a change to DNS tunnelling and  more. All of the binaries included in WSL 2.0.0 are properly signed, and there is an updated version of the kernel (5.15.123). For anyone trying out the latest version of Windows Subsystem for Linux, there are also a lot of fixes for issues found in previous versions.

In a blog post about the Windows Subsystem for Linux September 2023 update, Microsoft explains various additions including autoProxy:

This feature aims to increase your network compatibility when using an HTTP proxy. Currently, if you are using an HTTP proxy on Windows it will not directly apply to your WSL distros. Normally if you’d like to set up an HTTP proxy with WSL you'd need to set it up using the same way you would on a Linux machine, else you could experience connectivity issues. This feature aims to fix that, by automatically using the HTTP proxy information on Windows to set the HTTP proxy inside of Linux.

Microsoft has also shared an introductory video outlining the new features and changes:

The changelog for this latest release reads as follows:

• Added support for new opt-in experimental features to %USERPROFILE%\.wslconfig. For full info see the WSL docs update: https://aka.ms/wslsep2023updatedocspage
  • experimental.autoMemoryReclaim - Makes the WSL VM shrink in memory as you use it by reclaiming cached memory
  • experimental.networkingMode - A new networking mode for WSL that adds new features and improves network compatibility
  • experimental.dnsTunneling- Changes how WSL resolves DNS requests to improve network compatibility
  • experimental.firewall- Applies Windows firewall rules to WSL, and allows for advanced firewall controls for the WSL VM

• Store WSL is now accessible from Session 0 (solves #9231)
• All binaries shipped in the WSL package are now signed
• Introduce experimental.autoMemoryReclaim setting to %USERPROFILE%\.wslconfig
• Prompt the user to enable VMP if HNS isn't available on the machine
• Fix localhost relay failing if ipv6 is disabled
• Improve error message for WSL1 disabled policy to provide upgrade instructions
• Fix microk8s scenario for mirrored networking
• Create shared mounts when init sets up the distro namespace (solves #10410)
• Detach user block devices before terminating the VM
• Protect '.wslconfig' from being incorrectly translated
• Add logic to generate a systemd unit to protect the binfmt interpreter (solves #8843)
• Fix potential wslservice.exe crash.
• Retry plan9 mounts on IO error
• Update Microsoft.WSL.Kernel version 5.15.123.1-1
• Display a notification prompting the user to install missing optional components
• Add --manage <distro_name> --set-sparse to wsl.exe
• Fix various issues with the 'Update available' notification logic
• Update WSLg to 1.0.57
  • WSL GUI apps now have Windows snapping with the keyboard (Press WIN + an arrow key to snap to the side)
• Update MSRDC to 1.2.4485

You can download the Windows Subsystem for Linux 2.0.0 pre-release here.