Re: Repair Grumb

[David <bouncingcats@gmail.com>]

On Fri, 12 Jul 2019 at 05:09, Stephen P. Molnar <s.molnar@sbcglobal.net> wrote:
>
> I have Stretch installed  on sda1 and Buster installed on sdd1 on my
> 64bit Linux platform.
>
> Unfortunately, grub on sdd1 became corrupted and the boot process fails
> after Buster is selected.

Everyone reading this wonders:
1) why are you hiding the most important facts in your question?
2) what exact symptoms cause you to conclude that "grub on sdd1 became
    corrupted"?
3) did it ever work properly after installation, ie are we discussing a borked
    installation attempt, or did it work for a while and then "became"
non-working?
4) what is the method that you use to change from attempting to boot sda1,
    or attempting to boot sdd1?
5) at what point in that method does "boot process fails" occur, and
    what are its exact symptoms?
6) is EFI involved?

Your chances of receiving useful assistance are always improved by
providing a detailed description of *the failure*. Without them, readers
can only guess at what the problem might be, and readers with expertise
are unlikely to respond because they have more interesting things to
do than try to guess what someone is talking about.

It is possible that the only "repair tool" you need is grub itself.
You might just need to run 'grub-install' and specify sdd (not sdd1)
as the target device (but I'm not certain, due to the lack of facts).
See here:
https://www.gnu.org/software/grub/manual/grub/grub.html#Invoking-grub_002dinstall
Please be aware that if this command is misused it could make
your machine unbootable. But if used correctly it should be fine.

> Comments and guidance will be much appreciated.
> Thanks in advance.

I did my best. Hope it helps. If you provide the additional details
requested, we might be able to offer better help. Good luck :)