Removing UFS label from root

[Warren Block]

On Sun, 9 Sep 2012, Kevin Oberman wrote:

> I added a label to my root fs some time ago. I really prefer the gpt
> label and I have added it, but I can't figure out how to remove the
> ufs label.
>
> I boot single user and run 'tunefs -L "" /dev/ada1p2' but I get an
> "unable to write superblock" error. This is before mounting the drive
> RW, but it is, of course, mounted RO.

This worked in a VM when I tested it just now.  Maybe running fsck on 
that filesystem first will help.