> 
> I'll start here - - - -its clear that you didn't read what I said - -
> -I wanted to use two
> different kernels from the SAME distribution and that I just couldn't
> get to work and I
> couldn't find nada on line about it either. Doing it for different
> *nixes - - - sorry that's
> easy and I have done that in the past its trying to do it for the same
> os and just have
> two significantly (4.0.9 (iirc) and 4.16 (again iirc)) different
> kernels that proved part of
> the unfindable (sic) continuum. I just couldn't find a way to stick
> those two together.


OK, OK. Think what you want. Here is my final attempt, in the spirit of
keeping the discussion productive.

The way to do what you want is to simply edit the grub.conf and add a menu
entry that uses the kernel that you want to use. You can boot from the same
root filesystem (say /dev/sda1, or whatever), you can boot from a different
one, a duplicated one, a different drive, etc. With some simple GRUB command
line typing/editing and by knowing what you are doing, it can be done.

Here is how.

Start here for a very brief sample:
https://www.youtube.com/watch?v=jqysW8RmRBU
(This guy is doing it in a virtual machine, which is what I had recommended
that you do to "practice" and not screw anything up, but you shut the idea
down for nonsense reasons.)

Here is a more verbose solution that matches your needs:
https://www.youtube.com/watch?v=i97y5Y2nChs
At the beginning he tells you how you can "lose" a bootloader... maybe not
important to you. Then, fast-forward to 8:29, where he tells you what he is
going to do, and walks you through the steps of modifying the grub.conf.
Now recall from the previous video what keywords were given to GRUB from the
command line, like "linux /vmlinuz" and so on. These are arguments/switches
that go into a GRUB "menu item" as you will see. This guy's grub.conf is
built from an automated configuration from the grub-mkconfig or whatever,
and so it is very populated with crap. But he goes right ahead and cleans
them up, does what he wants, etc. You want to get a menu item that has the
booting from the standard kernel of the distro, and duplicate it with the
new kernel in the new menu item. When you are done, you do not even have to
re-install the bootloader; it is that simple.

Here is a less useful, more laborious process, video that uses external toosls:
https://www.youtube.com/watch?v=OUWpUdCWFbI

Here is another good one that will teach you a thing or two:
https://www.youtube.com/watch?v=prHDES9XmjU
This one starts with the standard GRUB configuration that does the auto-
detect thing again, which somebody pointed out on this list.

I hope this helps.