I want to have dual-boot two different Ubuntu distributions on the same hard drive. I've installed the first, with external /boot partition (e.g.
Then I've installed the second distribution, with separate /boot partition (e.g.
I thought, that after installation of the second Ubuntu, the
update-grub would automatically add entries for the first Ubuntu by chainloading /dev/sda2 from /dev/sda5. It did not happen.
Now, I wonder, what is the recommended way of chainloading the /dev/sda2 from /dev/sda5. I believe the recommended method would involve using the existing scripts on /etc/grub.d because the /boot/grub/grub.cfg will get replaced if I change it manually.