WSL2 Adding Support For Mounting Physical Disks, EXT4 Access And More From Windows
The newest Windows Insiders Preview Build adds support for the wsl --mount option for attaching and mounting physical disks attached to the system. This is intended for accessing data on Linux file-systems that are not natively supported by Windows, like EXT4 and many others.
Particularly for those using multi-boot setups or performing Linux backups to EXT4 or other non-Windows file-systems, making use of WSL's new mount options can allow interacting with these files. Additionally, once mounted by WSL, the files are also accessible from the Windows install via the File Explorer.
The mounted Linux file-systems are accessible from the Windows system via the \wsl$ path. One notable limitation though is that for now with the new Windows Insider builds that it's not possible to attach a single partition but just disks.
More details on this new WSL2 capability via the Microsoft Command Line Blog.