When you boot into Ubuntu from a WUBI install, you can see the Linux partition on your USB flash drive straight away. However, the reverse case is not true- if you boot into Ubuntu from your USB drive then your Ubuntu folders are invisible inside the “root.disk” file on your Windows partition.
So How do you mount a WUBI root.disk in a USB booted Ubuntu?
Well, it’s quite easy! Go into the terminal and type:
sudo mkdir /vdisk
sudo mount -o loop -t ext4 /media/Data/ubuntu/disks/root.disk /vdisk