Grub Repair

Recently there was a large set of updates which I installed in the shell. During that process a screen was presented saying I needed to select which drives I wanted to install Grub on and the list showed every drive in my system, 13 of them. I thought I selected the correct two drives to place Grub on, but it didn't work. My OMV 7 was bootable but when I attempt to boot my OMV6 install via the system BBS popup it boots OMV7.

I tried installing Grub to the two OMV disks like this:

grub-install /dev/sdn
grub-install /dev/sdm

But when I rebooted and selected the OMV6 disk, it booted OMV7.

Does anyone know what the shell command is that presents the table of all disks and allows selecting which disks to put grub on?

Somehow and I don't know how the filesystem UUIDs on both disks are the same and also all thru both grub.cfg files.

I know when I changed this on my OMV6 disk after cloning it to update the clone to OMV7, but I may have restored the OMV6 disk from a backup that had the unchanged UUID.

Simple enough to fix.

Thanks for your help.