Re: What does it mean when GRUB fails to find a kernel symbol?

[Goh Lip]

On 08/09/2023 17:33, Saj Goonatilleke wrote:
> Hello,
>
> One of our machines presented the following error after a reboot.
> I expect this was due to a misconfiguration -- not a bug in GRUB.

>      error: symbol `grub_disk_native_sectors' not found.



Assuming a misconfiguration and not a GRUB problem,
Go to grub prompt (not rescue prompt) by tapping 'esc' key when turning
on computer.

Input following at the prompt (without 'grub>')

grub> insmod part_gpt
grub> insmod ext2
grub> insmod chain
grub> search --set=root --label <LABEL>
grub> chainloader /boot/grub/x86_64-efi/core.efi
grub> boot

Notes
o  search line is to set root to the OS partition (not efi partition)
that you want to boot.

o  if you have not set label (as above search line),
   but you are sure of the partition numbering, you can set root
instead with
grub> set root=(hdx,y)

o if unsure of partition numbering (say, 2 disks or more or many
partitions)
you can use search for a file
grub> search --file --set=root <file>
A good file to search would be /etc/debian_version (if using debian) or
/etc/os-release like...
grub> search --file /etc/debian_version
grub> search --file /etc/os-release

o and from output, say "hd0,gpt8" and "hd0,gpt6",  confirm correct one with
grub> cat (hd0,8)/etc/os-release

o set again root with
grub> set root='hd0,gpt8'

o and boot
grub> chainloader /boot/grub/x86_64-efi/core.efi
grub> boot


When booted, do the necessary 'grub-install', 'update-grub'.