boot an alternate kernel

[Bob]

** Reply to message from Aaron Rainbolt <arraybolt3 at gmail.com> on Fri, 27 May
2022 03:08:00 -0500

> On Fri, May 27, 2022 at 12:42 AM Bob <ubuntu-qygzanxc at listemail.net> wrote:
> >
> > ** Reply to message from Aaron Rainbolt <arraybolt3 at gmail.com> on Thu, 26 May
> > 2022 21:35:39 -0500
> >
> > > > SDA1 is the bios-grub partition.
> > >
> > > Well, in that instance, maybe GRUB is finding the boot menu from your
> > > test partition, not the one from your main partition. Try mounting
> > > SDA2 and try the commands I mentioned (though do be aware that you
> > > might be unable to boot from the test partition if you do this).
> >
> > The man page for the update-grub command states it runs "grub-mkconfig -o
> > /boot/grub/grub.cfg".
> >
> > If I look at /boot/grub/grub.cfg I see markup language for the boot menu.  The
> > menu ior each partition has the menu items for all bootable Ubuntu partitions
> > but they are in a different order.  Now that I fixed the problem I can no
> > longer tell why the update-grub for SDA9 did not work.  Did it fail to create
> > the menu in /boot/grub/grun.cfg or did it fail to copy the menu into grub?  My
> > guess is that grub-mkconfig updates the menu for the partition it is booted
> > from and that it or someother program copies the menu into grub.  I think it
> > should not make any difference which system is booted when the update is done.
> > I will have to monitor the updates more closely and check the boot menu
> > whenever it gets updated to determine what is actually happening.
> 
> GRUB loads the boot menu from the grub.cfg file, but the thing is, it
> only loads one grub.cfg file. So if you have two, and you're updating
> one and GRUB is loading the other, then the updated boot menu won't be
> displayed. GRUB was probably finding the test partition's grub.cfg,
> and you were updating SDA9's grub.cfg.

If that is the way it works that would explan the results that I saw on my
computer.

Thanks

-- 
Robert Blair


The government is like a baby's alimentary canal, with a happy appetite at one end and no responsibility at the other.  -- Ronald Reagan