Bad fstab, don't boot - mistake during gmirror config

[cvc]

Hi Everyone,

I've made a mistake, I think. We have purchased a new HDD to our FreeBSD 8.2, and I've try to create a RAID 1 with gmirror. After the first reboot I got an error:

Trying to mount root from ufs:/dev/mirror/gm0s1a
ROOT MOUNT ERROR:
...
Loader variables:
vfs.root.mountfrom=ufs:/dev/mirror/gm0s1a
vfs.root.mountfrom.options=rw

when I give the '?' command, I got this result:

List of GEOM managed disk devices:
ufsid/{some numbers} ufsid/{some numbers} ufsid/{some numbers}  ufsid/{some numbers} 
mirror//gm0s1f mirror//gm0s1e mirror//gm0s1d mirror//gm0s1c mirror//gm0s1b mirror//gm0s1a mirror//gm0s1 mirror//gm0 ad6 ad4 acd0

I've followed the installation and configure procedure form the Handbook. I've try to boot from FreeBSD DVD, and loader prompt, to load the gmirror, and then boot, but I'got the same rsult.

What can I do? How can I access the drives, and restore the /etc/fstab from my fstab.bak? Many thanks.
Carl

 

[cvc]

I made it alone

# mount /dev/ads4 /mnt
# cd /mnt/etc
# cp fstab.bak fstab
# shutdown -r now

and done, booted everything fine, only thing, what I realised, the original ad0 has changed to ad4 after when I installed the new HDD, which was the ad6 after the reboot.