HOWTO [to avoid confusion, follow just this note] Grub: file not found

[Ralf Mardorf]

On Wed, 2014-01-08 at 00:59 +0100, Ralf Mardorf wrote:
> PPS:
> 
> It's correct that the old GRUB and not the clone's GRUB is used, but you
> are free to use what ever GRUB you prefer. You manually updated
> grub.cfg? Since during the upgrade the grub.cfg only should be
> automatically written for the clone and not be available for the new
                                                                   ^^^
                                                             old grub :D

Sorry, my explanations should be ok, but are likely confusing and might
include more typos.

Follow this howto:

1. run sudo grub-install /dev/sda
2. run (I guess it's) sudo update-grub
   however, or reinstalling a kernel will run the correct command

then your old GRUB should be fixed and be able to install the new *buntu
too, if you want to use the new install's GRUB, you need to chroot and
than to follow 1. and 2.