Grub installation. First potential Fedora killer

[Gene Czarcinski]

On 01/02/2014 05:32 PM, Jean François Martinez wrote:
> I have a nice booter setup and a nice _main_ Linux installation.  Last thing I would want is a distribution I am _testing_, that is Fedora 20 forces on me it will be my main installation and forces me to choose between installing Grub on the MBR or not at all.
>
> In addition it didn't detect my other Linux installation so at first boot I was only able to choose between Fedora 20 and Fedora 20.  Fortunately running grub-install fixed it (ie this time my other installations were detected).  Sort of.  First of all because Fedora 20, ie a ditribution I was _testing_ was now the default and second of all because every time I upgrade the kernel of my _main_ distribution I am supposed to reboot on F20 and run grub-install.  Great.  Nothing I can't fix but your average Ubuntu or Suse user will just cancel installation as soon he notices F20 is going to force itself on his MBR.  And if the road is a one way one between Fedora and Ubintu then  it is doomed.
>
If your system has multiple disk drives, there is a way to do what you 
want to do.  That is, have you current (production) installation and 
then install Fedora 20 for testing without disturbing your current boot.

Assuming that you current system has grub2-install /dev/sda, when you 
install Fedora 20, tell the install to put the MBR on another disk such 
as sdb.  Everything will be installed and configured except that the MBR 
on /dev/sda will not be touched.

When you reboot into you current/production system, you need to either 
enable (not disable) os-prober or add a definition to 
/etc/grub.d/40_custom which will "chainload" the grub.cfg file on your 
new/test system.

This works; I use it.

Gene