i currently have on my laptop this disk partition:
- /dev/sda2 -> windows 8 preview
- /dev/sda5 -> fedora 17 /boot (200Mb)
- /dev/sda6 -> ubuntu 12.04 /boot (200Mb)
- /dev/sda7 -> nothing (200Mb)
- /dev/sda8 -> nothing (200Mb)
- /dev/sda9 -> nothing (200Mb)
- /dev/sda10 -> crypto LUKS (200Gb)
- /dev/vg -> lvm2 using decrypted /dev/sda10
just install ubuntu, select /dev/sda6 as /boot partition and don't install grub on /dev/sda (you might install it on /dev/sda6).
again, nothing fancy: select /dev/sda5 as /boot partition, but this time install grub on /dev/sda.
update grub menu
there is nothing much to do actually.
/etc/grub.d/30_os-prober was able to detect available kernels for both fedora and ubuntu. if you have no ubuntu entry in grub, just force grub to regenerate the menu with:
# grub2-mkconfig -o /boot/grub2/grub.cfgthe os-prober even labeled the ubuntu entries as ubuntu!
i love fedora :-)