Re: gptzfsboot can't boot from 4TB SSD

From: Andriy Gapon <avg_at_freebsd.org>
Date: Thu, 27 Jan 2022 15:13:10 UTC
On 27/01/2022 17:09, Ulrich Spörlein wrote:
> On Thu, Jan 27, 2022 at 3:13 PM Andriy Gapon <avg@freebsd.org> wrote:
>> On 27/01/2022 15:57, Ulrich Spörlein wrote:
>>> So can this be a shortcoming in the BIOS with large drives?
>>
>> Yes, it can.
>> many people encountered this kind of a problem in the past.
>> 2TB (2^31 bytes) is the common boundary.
>>
>>> I had thought that only applies to boot0, not the loader itself.
>>
>> loader also uses BIOS calls for disk access.
> 
> Would that issue go away with UEFI and its ~100MB partition being in
> front of the disk? It would still
> need to be able to read the loader and kernel from anywhere in those
> 4TB though...

I don't know.  There is a greater chance that UEFI would be more correct, but 
there is no guarantee.

> Or should I bring back a / UFS partition in the front instead, with
> /usr and /var on ZFS?

It's up to you, of course.
You can also have a separate ZFS boot pool (a pool containing a dataset for 
/boot or for /) in the lower half of the disk.

-- 
Andriy Gapon