No idea if this is the right forum to ask my question, I was kinda looking for a installation section but couldn’t find it.
I have Manjaro 16.10.3 installed on disk sda. The rest of disk sda and the complete sdb are empty and are meant for tryouts of other distro’s. I was curious about OpenSuse Tumbleweed and installed it on 3 new partition son disk sdb. I chose not to install GRUB in OpenSuse because I wanted to keep the Manjaro one. I thought, after installing OpenSuse, I would boot into Manjaro, select update-grub which would find OpenSuse as well and I would be able to boot into either of the two. Well, thought, would and would be able don’t work so well. Update-grub did not find Suse and after a reboot I was back in Manjaro. Nice, but not what I wanted.
Question: how do I set up a second OS with relation to Grub and maintain Grub from the first OS (Manjaro) so I can steer everything from that OS, even when I delete the second (third, fourth?) OS?
Is there a simple way of explaining this or maybe even a tutorial somewhere?
Thanks a lot.