Grub message: "no root file system"

Created by delance
grub boot root file system
Last updated by:

This error message means that Grub has found boot partition, but can't launch Linux with the files found.
The first step is to reinstall Grub from CD or USB stick:
If it fails again and error occurred after an update of system (specially a new kernel), try to boot from 3rd line of Grub menu, i.e. the previous kernel.
If it fails again, to get help on forum provide:
a-partition table:
b-file /boot/grub/grub.cfg
c-result of command:
    ls -l /boot