8.2-RELEASE - gmirror and gpart issue. Metadata overlap?

Andrey V. Elsukov bu7cher at yandex.ru
Sat Feb 26 18:15:48 UTC 2011

On 26.02.2011 15:26, Marin Atanasov Nikolov wrote:
> After a reboot I get this right before the FreeBSD bootloader starts:
> gptboot: invalid GPT backup header
> I suppose this error simply means that gpart can't find it's backup
> header, because gmirror and gpart both are using the last sectors for
> a provider to write it's metadata.

This message is from gptboot. Loader does not know about your software
mirror and it just checks GPT headers in the second and last LBA.
As i see now, there is inconsistency in the behavior between gptboot and

gptboot does reading of GPT backup header from the last LBA,
but GEOM_PART_GPT from the alternate LBA which is not equal to last LBA
in your case.

> Which would mean that gmirror and gpart metadata overlap, and that's
> why I see this message?


> Anyway, I can still boot from the primary GPT header, and here's the
> second message I get during boot:
> GEOM: ad0: secondary GPT header is not in the last LBA.
> Why does GEOM reports ad0, and not mirror/gm0 as the provider? I've
> used the gmirror'ed device for gpart, not ad0.

This is how GEOM tasting works. Do you have any problem except for
those messages? What does not work?

Also when you are writing problem report about gpart it will be not bad
to add output of `gpart show` or `gpart list` commands. And `gmirror
list` for GEOM_MIRROR.

WBR, Andrey V. Elsukov

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 488 bytes
Desc: OpenPGP digital signature
Url : http://lists.freebsd.org/pipermail/freebsd-stable/attachments/20110226/5195f6c7/signature.pgp

More information about the freebsd-stable mailing list