Gmirror vs 10 Release-P12

[Francisco Reyes]

New machine. Installed FreeBSD release, installed gmirror, ran update.. 
gmirror stopped working.

After a number of hours of trying different options and several 
re-installs, tried a different approach:
* Install 10 Release
* Update to Release-P12
* Try to setup gmirror

Even though the command "gmirror label -v gm0 /dev/ada0" comes back with
Metadata value stored on /dev/ada0

When I do "gmirror status" I get nothing.

Is gmirror broken in P12?
Anyone has gmirror working with P12?

I was able to setup the mirror more than once with Release, but P12 is 
not behaving at all like release for me.

Any pointers greatly appreciated