[CentOS] CentOS 7 cloned VM cannot boot

On 5/5/2017 3:15 μμ, Gianluca Cecchi wrote:

> ...
> grub2-install /dev/vda
> ...
> Was this one of the command you already tried?

Yes, I have tried that multiple times, both from Troubleshooting Mode 
(booting using CentOS 7 Installation CD) and from within the actual 
system (booted using super-grub2 disk).

I always get (from troubleshooting mode):

    # grub2-install --root-directory=/mnt/sysimage/ /dev/vda
    Installing for i386-pc platform.
    grub2-install: error: unknown filesystem.

or (from within the OS):

    # grub2-install /dev/vda
    Installing for i386-pc platform.
    grub2-install: error: unknown filesystem.

How can I fix that?

Nick