GEOM: the secondary GPT table is corrupt

[Tom Worster]

i'm using gmirror on a server box here at home without understanding how
geom works in any detail. i probably followed the handbook chapter 19.4 but
it was a while ago.

i'm wondering if there's a way to clear these warnings in boot logs:

ad4: 715404MB <SAMSUNG HD753LJ 1AA01107> at ata2-master SATA150
GEOM: ad4: the secondary GPT table is corrupt or invalid.
GEOM: ad4: using the primary only -- recovery suggested.
ad6: 715404MB <SAMSUNG HD753LJ 1AA01107> at ata3-master SATA150
GEOM: ad6: the secondary GPT table is corrupt or invalid.
GEOM: ad6: using the primary only -- recovery suggested.
GEOM_MIRROR: Device mirror/gm0 launched (2/2).
GEOM: mirror/gm0: the secondary GPT table is corrupt or invalid.
GEOM: mirror/gm0: using the primary only -- recovery suggested.
GEOM_LABEL: Label for provider mirror/gm0p1 is msdosfs/EFI.
Trying to mount root from ufs:/dev/mirror/gm0s1a
GEOM_LABEL: Label msdosfs/EFI removed.

the array seems to be fine, according to gmirror status.

googling around, it seems these warnings indicate shoddy initial setup of
the disks and there's no clear answer how to sort these matters out.

any advice?

-tom