Re: [gentoo-dev] grub:2 keywords

[Richard Yao]

On 06/29/2012 05:04 PM, Mike Gilbert wrote:
> On Fri, Jun 29, 2012 at 4:56 PM, Richard Yao <ryao@g.o> wrote:
>> On 06/29/2012 03:04 PM, Mike Gilbert wrote:
>>> On Fri, Jun 29, 2012 at 3:00 PM, Rich Freeman <rich0@g.o> wrote:
>>>> On Fri, Jun 29, 2012 at 2:51 PM, Richard Yao <ryao@g.o> wrote:
>>>>> GRUB2 does away with the conventional stage files. It also wants a
>>>>> special BIOS Boot Partition in order to function. That is where it
>>>>> stores the equivalent of the stage2 bootcode. That is similar to
>>>>> FreeBSD's bootloader.
>>>>
>>>> Now, that should make for a fun migration!  Fortunately I do have a
>>>> separate boot already, and I guess I can be daring and overwrite it in
>>>> place and trust in grub2 to still find the kernel elsewhere.
>>>>
>>>> Those without a separate boot and without any free space are likely to
>>>> find this to be painful.  Resizing partitions isn't exactly
>>>> risk-free...
>>>>
>>>> Rich
>>>>
>>>
>>> I think Richard is incorrect here; grub2 can live on any filesystem,
>>> so long as some combination of modules can access it.
>>>
>>
>> Do you know what function the BIOS Boot Partion serves? It is necessary
>> when using GRUB2's ZFS support. I was under the impression that it
>> stored boot code.
>>
>
> Based on a Google search I think "BIOS Boot Partition" is a GPT thing.
> Not relevent if you have an MBR partition table.
>

This is correct. I had forgotten that I switched to GPT on my systems
because ZFS partitions drives using GPT by default. Allowing people to
specify the partitioning without requiring them to do it manually is on
my to do list.

However, those who wish to use GPT on their systems will need a BIOS
Boot Partition to store the boot code. That will not apply to older
systems that are switching to GRUB2 unless they also change their
partition tables.