On Fri, Sep 14, 2018 at 2:02 PM, gregrwm <tclug1 at whitleymott.net> wrote:
>> There are 20+ partitions on the hard disk so both systems have everything
>> separate except /boot and /efi (whatever that partition is called).
> so boot is shared?  if so, eek.  apt-get update on one will throw out
> kernels still expected by the other.  and similar ugly contention for
> maintaining grub.  this would explain why grub couldn't find the other OS.

OK that's why I've not been  able to get this working!
>> advises that users do not directly edit grub.conf, and use their own
>> "discovery" and mangement
>> of GRUB scripts.
>> But I always tweak the grub.conf myself.
> grub.conf is regenerated, and your mods lost, whenever a new kernel is
> installed.  i know, i hated it when i first started learning grub2.  your
> mods belong in /etc/default/grub and /etc/grub.d/40_custom.  copy 40_custom
> to 07_custom and stuff in there will precede, and thus be what boots by
> default.  put in there entries which boot via the kernel and initrd in /,
> those softlinks are updated whenever a new kernel is installed.  then either
> regenerate grub.conf, or i confess i then edit the same mods into grub.conf
> as well, it's just plain far quicker.
> also if you're interested in how to boot multiple installs all from the same
> partition, just ask.

Bingo - -- - I've been looking for this and can't find any guides nor
ideas - - -
so - - - please? (Supplicatory posture entered! (grin!))