It\'s a pretty simple problem, I just can\'t find the Lxss folder in LocalAppData which is suppose to store files from the Bash on Ubuntu on Win
It was actually moved in the latest release to :
C:\Users\%USERNAME%\AppData\Local\Packages\CanonicalGroupLimited.UbuntuonWindows_79rhkp1fndgsc\LocalState\rootfs\
See this blog post from WLS git repo