Zpool on raw disk and weird GEOM complaint

[Marius Nünnerich]

On Mon, Jun 29, 2009 at 16:50, Patrick M. Hausen<hausen at punkt.de> wrote:
> Hi!
>
> On Mon, Jun 29, 2009 at 04:41:14PM +0200, Marius Nünnerich wrote:
>> OK, there is the GPT signature which reads "EFI PART" at offset 0x200.
>> What was on the disk before?
>
> Nothing. Factory new.
>
>> I think it should look different. There is a document from sun which
>> explains the ZFS ondisk format and and I don't remember it to look
>> like a MBR and GPT ;) Sorry, I don't have the time right now to dig
>> through it.
>
> As I found with Google, ZFS does put a EFI/GPT label on the
> disk if you give it an entire disk as a vdev. Looks like
> it's not understood by GEOM_PART_GPT.

Hmm, it's rather stupid to put a GPT entry in the second sector but
not the corresponding one in the last sector. So our GPT
implementation has the right to think this GPT is broken. As far as I
understand the ondisk spec from sun there is no space for the
corresponding one in the last sector (it's part of the uberblock
array).

I just checked my ZFS mirror it has all zeros in the first few sectors
on both disks. It was created with zfs version 6 in freebsd.