Re: Converted MBR to GPT and menu is gone, can't use grub-reboot either

[Pascal Hambourg]

On 21/02/2023 at 12:16, Chandler wrote:
> Pascal Hambourg wrote on 2/20/23 8:48 AM:
> Ok I ran `grub-install --verbose /dev/sda` and `grub-install --verbose
> /dev/sdb` and tried rebooting, still can't see anything.

TBH I did not expect any improvement.

> After the BIOS
> finishes loading, then I see a blinking cursor for 5 or so seconds,
> probably while the menu is counting down, then I start to see the kernel
> boot messages.

Can you increase GRUB_TIMEOUT and update grub.cfg and check whether the 
delay at boot time changes accordingly ? Or check if the load kernel 
message is displayed right away after pressing <Enter> ?

If yes, can you try other resolutions in GRUB_GFXMODE or even text mode 
(GRUB_TERMINAL=console) ?

> the "Partition 3 does not start on physical sector boundary" message
> doesn't make sense because I'm fairly sure I used `parted` to check if
> the partition was aligned.

If partition 3 is the BIOS boot partition, it does not matter that it is 
not aligned.

> and maybe the "Partition table entries are not in disk order" is also
> interfering somehow?

No.

> I'm not sure why that guide had me make this "BIOS boot" partition if I
> could just stop at step 5 without UEFI anyway so maybe that could be the
> problem?

No. A dedicated BIOS boot partition is mandatory for BIOS boot on GPT if 
/boot is not in a plain partition (e.g. in LVM or RAID), and recommended 
because more reliable than blocklists in other cases.