gmirror failed with error 19.

Lev Serebryakov lev at
Sun Oct 16 09:59:43 UTC 2011

Hello, Andrei.
You wrote 16 октября 2011 г., 13:29:05:

>> > as livecd and recovering gpt. But I still can't boot from geom mirror.
>>   GEOM classes (mirror, stripe, raid3, etc) is not compatible with
>>  GPT. GPT want to store its copy on last sector(s) of drive. If your
>>  put it on gmirror volume, last sector is occuped by gmirror metadata.
> When I boot from memstick with FreeBSD 9 BETA3 I see error "gptboot: invalid
> backup GPT header". So FreeBSD 9 is not compatible with geom mirror anymore
> because by default installer configure GPT partitions?
  Nobody stops you from installing FreeBSD on disk with MBR, even if
memstick is prepared with GPT (which have another problem, as images
for different memsticks should have different size to have GPT in last
sector). And FreeBSD's gptloader has relaxed checks and doesn't refuse
to boot if second GPT copy is valid, but not in last sectror(s) of

  All these questions were discussed a few days ago in current@
mailing list, without any clear conclusion :(

 Here is proposal (from me and other users), that there should be BIG
WARNING in documentation and in utilities when GPT is created not on
raw disk, but over some other GEOM. But, again, I didn't see clear
approval from "senior developers" (not to speak about Release
Engineers) for such change...

 (I've CCed current@ mailing list, as most of discussion on this topic
 was there).

// Black Lion AKA Lev Serebryakov <lev at>

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