CentOS - Mar 2014 - RHEL/CentOS 7 Dual boot with CentOS 5.x/6.x - default boot quick solution/howto

I have RHEL 7 Beta installed in dual boot with CentOS 6.x. Since RHEL 7 
installed GRUB2, I had problem that RHEL 7 is default boot.


My personal solution was to go to /etc/grub.d and run command:
mv 10_linux 31_linux

grub2-mkconfig -o /boot/grub2/grub.cfg

Explanation:


- /etc/grub.d is where grub2 writes down config files used to create 
boot menu.
- OS-prober creates 30_os-prober file in /etc/grub.d
- 10_linux is created for RHEL/CentOS 7.x system installed.

If you change order of files in /etc/grub.d (numbers at the start of the 
files) the list generated with grub2-mkconfig will change order in the 
GRUB2 menu :)


Fedora/RHEL 7.x have a changed GRUB2 so for further reading read:


5.3 Multi-boot manual config:
http://www.gnu.org/software/grub/manual/grub.html#Multi_002dboot-manual-config


and

Fedora GRUB Wiki:
http://fedoraproject.org/wiki/GRUB_2


-- 
Ljubomir Ljubojevic
(Love is in the Air)
PL Computers
Serbia, Europe

StarOS, Mikrotik and CentOS/RHEL/Linux consultant

On 22.03.2014 17:46, Ljubomir Ljubojevic wrote:
> I have RHEL 7 Beta installed in dual boot with CentOS 6.x. Since RHEL 
> 7
> installed GRUB2, I had problem that RHEL 7 is default boot.
> 
> 
> My personal solution was to go to /etc/grub.d and run command:
> mv 10_linux 31_linux
> 
> grub2-mkconfig -o /boot/grub2/grub.cfg
> 
> Explanation:
> 
> 
> - /etc/grub.d is where grub2 writes down config files used to create
> boot menu.
> - OS-prober creates 30_os-prober file in /etc/grub.d
> - 10_linux is created for RHEL/CentOS 7.x system installed.
> 
> If you change order of files in /etc/grub.d (numbers at the start of 
> the
> files) the list generated with grub2-mkconfig will change order in the
> GRUB2 menu :)
Oh boy, I'm so going to miss Grub 0.97..
Thanks for sharing, though!

-- 
Sent from the Delta quadrant using Borg technology!

Nux!
www.nux.ro