On Mon, Aug 28, 2017 at 07:48:22PM +0100, Simon Hobson wrote:
> Hendrik Boom <hendrik@???> wrote:
>
> > Do I understand correctly that grub-install will scan my only hard
> > drive looking for (at least) bootable Linux systems? And that as a
> > result, running grub-install on the old system will detect both and
> > create a grub menu that contains both?
> >
> > (of course, using the grub files on the old system, which I'd better
> > not delete if I still want to boot)
>
> grub-install will install the first stage.
> update-grub will update the grub menu, and depending on how you've set options, it will scan all filesystems looking for OSs to put in the menu.

Now I can't figure out how to set options so that update-grub uses
os-prober.

Adding the line
GRUB_DISABLE_OS_PROBER="false"
to etc/defaults/grub has no effect.

-- hendrik