Strange booting problem

[Chris Murphy]

On Tue, Jun 30, 2015 at 5:02 PM, Gordon Messmer
<gordon.messmer at gmail.com> wrote:
> On 06/30/2015 03:41 PM, jd1008 wrote:
>>
>> So, it begs the question:
>
>
> (that's not what "begs the question" means)

Yes. It's an accusation.

>
>> Can I create a disk with msdos partitioning scheme,
>> none of the partitions marked as bootable, and have bios
>> quickly skip over it to the next device in the boot sequence?
>
>
> So far it looks like the answer is "no" or "it depends on your BIOS."
>
> Both SeaBIOS and your Dell BIOS, based on what we've seen, will attempt to
> use the boot sector of a disk with a valid MBR, even when the boot sector is
> all zeros.  That's consistent with all of the documentation I can find.
> It's possible that other BIOS might skip an all-zero boot sector, but we
> don't have any documentation of which systems behave that way.

That seems to be true.


> However, also based on testing, it seems that if you used GPT for your
> partitions, then BIOS would skip over the drive during the boot process.

No because every GPT creator also creates a PMBR which includes the
MBR boot signature that you're telling us causes (some) BIOS's to use
the entire MBR and then hang if it has nowhere to go.

> So, maybe that's a solution?  The only reasons I can think of to use MBR are
> a) you have an operating system that can't read GPT and b) you need to boot
> from the drive under BIOS.  I don't think either of those apply to you.

If you have such a BIOS, the work around is to not partition it either
MBR or GPT. If it needs partitioning, use LVM on the whole block
device. It has a signature the BIOS won't know about.

-- 
Chris Murphy