Ubuntu – Dual boot Ubuntu / Ubuntu installation, non-UEFI PC. How to delete one of the GRUBs

dual-bootgrub2

A non-UEFI computer I use for experimental install purposes only has two Ubuntu installations set up as dual boot. Currently they are 18.04 LTS and 19.04.

Not knowing any better, I installed GRUB with both installations, and now they can get into a "duelling GRUB" situation with the last one to run grub-install grabbing control.

How can I delete GRUB from one of the installations?

I am leaning towards re-installing the 19.04 system without GRUB, but would take an easier way if it exists.

Best Answer

  • First decide which of the both systems should control the grub instance in the MBR. Boot this system and run

     sudo grub-install /dev/sdX
    

    to make sure this system now controls grub. In the second step boot the other system and run

    sudo dpkg-reconfigure grub-pc
    

    During reconfiguration of the package you will have the choice to install an instance of grub to the PBR of the system-partition or not to install an instance of grub at all.

    That's all, you're done, only one OS will reinstall an instance of grub to the MBR from now on when a system-upgrade ships with a new version of grub.