boot an alternate kernel

[Ralf Mardorf]

On Thu, 26 May 2022 20:23:41 +0200, Ralf Mardorf wrote:
>>Should it work from only one partition or should it work from either
>>partition?  

>I suspect that the above isn't the issue you are experiencing. You
>probably installed GRUB 2 times. One is the GRUB used by the boot order
>of your BIOS settings, the other GRUB is unused. You are likely booted
>to the wrong install and generating the menu.cfg for the unused GRUB.

In your case it's likely possible that you can use both GRUB
bootloaders, but you need select one bootloader by the BIOS' setting
boot order and you need to update the menu.cfg of both GRUB.