Re: Two GRUB setup can boot one each of two installs, but not theother, why?

[Tom H]

> Still incorrect:
>
> Grub 0.9* (ala grub legacy) does not use uuid AT ALL.    Grub 0.9*
> operates entirely with BIOS commands.  Literally hd(N,x) where N is a
> bios drive, and x addresses a partition.  Very often it determines the
> block-location of a resource it wants at (grub shell setup) install
> time, and directly gets those blocks from the bios-device in question.
>
> Grub 1.9* (ala grub2) doesn't mention uuid anywhere in the online 
> documentation.
>
> It seems that in both cases, UUID is __ONLY__ used AFTER your kernel
> and initramfs/initrd are loaded.
>
> It _MAY_ be that grub2 supports UUID in the configuration file and is
> smart enough to map that back to a device, but if your device ordering
> is not going to be the same later then you will likely still have the
> requirement to somehow (I have not yet needed to do that with grub2,
> so do not know) manually specify what the devices will be when
> restarted.

Ubuntu must have patched grub1 to use UUIDs because, pre-9.10 and
grub2, you could/would use a "uuid=..." instead of a "root=..."
statement and the kernel's root reference was "root=UUID=..." so there
was no "hd(x,y)" reference in menu.lst.