Re: [gentoo-user] Re: OFF TOPIC Need Ubuntu network help

[Dale <rdalek1967@gmail.com>]

Grant Edwards wrote:
> On 2023-10-18, Michael <confabulate@kintzios.com> wrote:
>>> The protective MBR and the BIOS boot partition are two different,
>>> unrelated things. The BIOS boot partition is a real partition (usually
>>> 1-2MB in size) that's present in the GPT parition table. It's used by
>>> Grub as a place to store its files.
>> Yes, this is needed on GPT disks when installed on BIOS MoBos.
> There is a way to install Grub on GPT disks without it, but it takes
> extra work and isn't worth it. You have to lock certain files in place
> under /boot/grub so that block-lists can be embedded in sector 0.
>
> All of the disk label utilities I've seen recently will, by default,
> leave a sizable empty space between the primary GPT table and the
> start of the first partition (which typically starts at a 1MB offset
> from the start of the disk).  I've never understood why Grub won't use
> that space they way it will use the empty space between an MBR and the
> first partition.
>
>>> It must be the first partition, and it doesn't have a real
>>> filesystem (grub uses some sort of private filesystem):
>> I'm not sure it uses any filesystem.  I understood it uses a raw sector jump 
>> from the MBR to the GPT partition type 0xEE.
> I've read a couple vague but differing descriptions of it. One
> description specifically referred to "files" (plural) and some sort of
> grub-private-internal filesystem.  However, it could be that it's
> nothing but a single "file" starting at block 0 in that partition.
> Whatever it is, it seems to be "opaque" in that Grub puts stuff in
> that partition, Grub later uses that stuff, and nobody else needs to
> know or care what it is or how it's organized. I haven't looked
> through the Grub source code to try to see inside the black box...
>
> --
> Grant
>

I used cgdisk and GPT for my disk even tho it is small, only 300GBs or
so, mostly out of habit.  The grub install failed and I did a search.  I
found this and it worked. 



grub-install fails with "grub-install: warning: this GPT partition label
contains no BIOS Boot Partition; embedding won't be possible."  Using
parted command.

# parted /dev/sda
# set 1 boot off
# set 1 bios_grub on
# q

# then install grub.  This happens on drives where GPT is used instead
of MBR.



This may be something you want to make note of.  I guess it changes the
way grub sees it or something.  Anyway, it worked fine after that so may
be worth making a note of in case one of you ever needs it. 

Dale

:-)  :-) 

P. S.  My off topic Ubuntu thread is covering a lot of strange things. 
LOL