Using Software RAID-1 with FreeBSD
Subject:   something missing?
Date:   2006-03-30 12:20:47
From:   ragnar_spain
Response to: something missing?

it also happened to me, but i found the solution, before running the gmirror label run this:
# gmirror load

and also is suggesting to do the next comand to the hds:
# gmirror clear adX

another tip is that if u already installed freebsdm u can also add gmirror through the installation disk entering the option to fix the system and then:
# chroot /dist
# mount_devfs devfs /dev
... gmirror comands ...
# mount /dev/mirror/gm0s1a /mnt
noticing that ur system will be at /mnt