Just install OpenSolaris 2008.05 as the last thing after you've already installed everything else and you should be able to get the special Solaris GRUB with the magical ZFS secret sauce ingredients that allow everything to boot up the way you want it to.
Believe it or not, ZFS is the first 128 bit, self-healing, self-aware, incorruptible file system in the history of human civilization, and modifying GRUB to be able to boot into a 128 bit root file system is a real pain in the rear. It was a major feat of technological genius that the OpenSolaris programmers were able to get a ZFS root file system to boot up on x86 hardware at all (ever seen a 128 bit Intel CPU? I haven't) never mind modifying GRUB so that it enables you to choose whether or not you want to wake up the ZFS monster or boot into an NTFS or ext3 or UFS based operating system instead. Let me put it this way: the Mac OS X programmers and the FreeBSD programmers have been trying to boot up into a full ZFS root version of their operating system for years now AND they have the source code blue prints for how it works in Solaris given to them by Sun and yet they STILL (as far as I know) haven't been able to achieve the holy grail of a fully bootable ZFS root file system for their OS (they can mount ZFS partitions after booting up, but still no ZFS root and no ZFS /boot). Now take into account that the FreeBSD kernel programmers are some of the smartest people to ever touch a computer keyboard and you get an idea how difficult it is to get that whole "booting up into a root ZFS file system" thing going. Also, since almost everyone in the Linux community (except for me) has an anti-ZFS attitude, don't expect the Linux version of GRUB to be able to boot into a ZFS root any time soon either, which means you have to use the OpenSolaris version of GRUB that allows you to boot into ext3 and UFS and ZFS with no problems. So the moral of the story is: Just install BSD first, then Ubuntu and then install OpenSolaris 2008.05 last, and you should get the OpenSolaris version of GRUB and everything should work. -- This message posted from opensolaris.org
