[CentOS] How does Live CD find OS's?

Jonathan Billings wrote:

> I know that in el7, grub2 uses os-prober
> (http://joeyh.name/code/os-prober/), which is probably what it uses in
> the LiveCD.

Yes, thanks. 
I confused os-prober with grub2-probe, which is an executable file.
Hopefully I should be able to work out why I am getting this
  cannot find a GRUB drive for /dev/block/8
error when I run grub2-mkconfig

-- 
Timothy Murphy  
gayleard /at/ eircom.net
School of Mathematics, Trinity College, Dublin