I've read carefully the article about bios_grub partition you've given link
to. And it turned out for me that it's only used for non-UEFI boot. It this
case it's impossible to boot without stage1 (in mbr), because our PXE
doesn't touch hard disks. So clearing BIOS_boot partition will not
introduce any advantages. I suggest that we just clear boot code in mbr,
let's don't add unneeded code.

On Thu, Mar 24, 2016 at 2:13 PM, Alexander Gordeev <[email protected]>
wrote:

>
>
> On Wed, Mar 23, 2016 at 7:49 PM, Dmitry Guryanov <[email protected]>
> wrote:
>
>>
>> I have no objections against clearing bios boot partition, but could
>> you describe scenario, how non-efi system will boot with valid
>> BIOS_grub and wiped boot code in MBR
>>
>
>
> I thoroughly agree that it's impossible to boot without stage1 from the
> disk for non-uefi system. Besides, it doesn't mean what we shouldn't wipe
> dedicated BIOS_grub partition.
>
> But... How about network booting over PXE? I'm not quire sure if it's
> still technically possible. I read that stage1 just contains of LBA48
> pointer to the stage1.5 or stage2. So, i can imagine a case when somebody
> has tweaked PXE loader so it will be jumping to predefined LBA48 pointer
> where stage1.5/2 resides absolutely bypassing stage1.
>
> I knew that partitioning layout for the first 2 partitions is always the
> same for all target nodes. The actual value of the partitioning boundaries
> may slightly vary due to partition boundaries alignment depending on the
> h/w itself. If all nodes were equipped with the identical h/w (which is
> almost true for real deployments), then BIOS_grub partition resides under
> the same LBA48 pointer for all nodes. So, even it may be sounded too tricky
> and requires a lot of manual steps, but it's still possible. No? Did I miss
> something?
>
>
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-- 
Dmitry Guryanov
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