You can also quickly get around the "no root file system" error by changing the validation.py file.
When running the liveCD, but prior to installation:
Code:
gksudo gedit /usr/lib/ubiquity/ubiquity/validation.py
go to the end of the file, and edit the line that says
Code:
if not root:
result.add(MOUNTPOINT_NOROOT)
Change to:
Make sure you leave the indentation in before the word "pass". Save the file, close it, and then you can run the installer.
Now, when you run the installer, it won't check for a "/" directory, so make sure you have one!