Microsoft today announced the Windows Subsystem for Linux Version 2 ̵
No, Microsoft does not make Windows 10 a Linux distribution. It will continue to be based on the Windows kernel. Microsoft, however, will "deliver a true Linux kernel with Windows that allows full compatibility with system calls." The kernel is compiled by Microsoft based on the latest stable kernel of kernel.org source code. It will initially be based on version 4.19 of the Linux kernel.
Microsoft's Linux kernel is optimized for WSL 2 and "optimized for size and performance to deliver a great Linux experience on Windows". The Linux kernel is updated via Windows Update. Yes, you get Linux kernel security updates through Windows Update. The full kernel source code is available online at Github.
This Linux kernel is optimized for small size, improved startup times, and low memory footprint. It replaces "the emulation architecture included in the design of WSL1."
This drastic change means that WSL now offers improved file system performance. It offers full system call compatibility. This means that you can run Docker and other Linux apps on Windows with WSL 2. However, this is not slow as with a VM – it's as fast as WSL 1 or even faster. Microsoft says:
File-intensive operations such as
apt upgradeand more will all be noticeably faster. The actual speed increase depends on which app you run and how it interacts with the file system. In our first tests, the WSL 2 unpacked a zipped archive up to 20 times compared to WSL 1, and when using git clone, npm install, and cmake, the 2- to 5 times. We look forward to speed comparisons from the community when we publish!
The first release of WSL 2 will appear in Windows 10 insider builds at the end of June 2019. For more information about the Linux kernel, see the Microsoft blog
Microsoft launches a new Windows Terminal App that will help the next version of WSL even better.
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