Where does Ubuntu File system live?
After you install the Ubuntu package on Windows 10 it is not that easy to locate where the file system is living. The subsystem acts differently to a traditional virtual machine where you can control locations upon initial config. But because it is a subsystem the integration with Windows and the filesystem is seamless and takes alot of the pain out of setting up a virtual machine and way less resources from your machine.
Basically, the Ubuntu operating system files live in the Ubuntu subsystem.
So what does this mean in reality? well a few key points; it does not live anywhere that you can easily notice upon installation. It is not given its own drive or partition for example. It lives within the Application Data store in Windows, so the key take away here is to treat the files as something that like any other App data is perishable so do not treat it as permanent which means for storing any work you want to do in Ubuntu you are going to want to store the files in Windows where you can include them in your backup routine.
You can find the contents of the Ubuntu operating system under your user profile in the AppData folder.
The distro folder is going to have Ubuntu in the name example;
Any of the Linux distributions that you install via the subsystem will also appear under AppData with the distro name in the folder.
The Ubuntu files themselves are located under the rootfs folder. This folder holds the expected Ubuntu operating system folder and files that will look familiar to you.
Windows file system in Ubuntu
After you install Ubuntu on Windows you should be able to directly access your Windows file system from Ubuntu under mount.
cd mnt ls -la cd /mnt/c/Users/UserName/Documents
You can create symlinks from Ubuntu folders to Windows ones to enable you to store any documents your working on in Windows. This way if something happens to the Ubuntu subsystem you can reinstall the package and not have it affect any work you have done.
ln -s /mnt/c/Users/UserName/Documents /home/UserName ln -s /mnt/c/Users/UserName/www/html /var/www/html