How to re-install Grub2 ?

Since my recent update from 42.1 to 42.2, I have had occasional boot issues.
I upgraded using zupper dup method’

Boot screen resolution is set to ‘auto’.
I get the sense that Grub2 is having difficultly auto detecting a display resolution.
Sometimes I get a high resolution graphical display, sometimes a high resolution text interface and sometimes a low resolution splash with no characters visible.

I also see that a file /etc/default/grub.rpmnew exists, dated 10/28/16 so likely came with 42.2 upgrade, but not acted upon.

Seems like a best path might be to Reinstall Grub2 for 42.2, I am not sure best way to do that?

Will a forced re-install of grub2 using YAST GUI re-run all the necessary setups and system configuration probes?


Check any cable connections.

In auto mode I believe the BIOS passes the info

Just set the resolution you want in yast.

Yes yast will do a reinstall and setup of grub

Thanks, Here is what I did:
Rebooted, entered the Grub CLI with a ‘c’
Ran videoinfo

It listed several modes, likely the intersection of what the monitor could do and what the driver supported.
One was 1024x768.

Sidebar, the videoinfo script (properly) reported that the preferred for my terminals is 1920x1080, but appears that is not the GRub driver.

So I modified /etc/default/grub with:


per your suggestion.

Then, followed this instruction from
After having edited /etc/default/grub, run grub2-mkconfig to update the main configuration file.

Rebooted, got the 1024x768 graphical boot environment.

Perhaps Grub was getting confused and still trying 1920x1080 (preferred) ?
This did not happen in 42.1

All seems well, thanks for help