How to restore grub in OpenSuse when another OS takes over

English Install/Boot/Login
1

I ask how to restore grub in OpenSuse for the following reason.
I have a Toshiba Tecra s-2 as main disk (sda).
There is installed OpenSuse 12.3 Tumbleweed that usually governs the grub.
In an external drive connected via USB (sdb) I have many other Linux operating systems, which I change in turn, installing gradually new ones to try.
A few days ago I installed into the external drive an Arch-based system that has taken over the grub.
As happened in the past I have tried simply to restore grub using the dedbian-based live cd boot-restore-disk.
This is to get again Opensuse in charge of grub.

Using boot-repair-disk I had, however, in the latter circumstance mentioned the following response

  • Please enable a repository containing the [linux] packages in the software sources of openSUSE 12.3 (sda1). Then try again.
    and, after a while I was invited to text
  • sudo chroot “/mnt/boot-sav/sda1” dpkg --configure -a
  • sudo chroot “/mnt/boot-sav/sda1” zypper remove -y grub*-common
    As a result my attempt to text the first “sudo chrot /mnt etc.” I got this
  • user@debian:~$ sudo chroot “/mnt/boot-sav/sda1” dpkg --configure -a
  • chroot: failed to run command `dpkg’: No such file or directory
    I guess that does not work because dpkg is a valid command for Debian and not for openSUSE.

What do you advise me to do?
Thanks

2

This Article would be our suggested method to recover Grub2 back to working: Re-install Grub2 from DVD Rescue

Thank You,

3

Actually
If another OS takes over, you can usually boot openSUSE from the other OS grub
So boot to openSUSE
Open a terminal and do

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

grub2-install /dev/sda
4

Thanks a lot.
I did as caf4926 suggested.
It works for me.