where is package group info?

[Tom Horsley]

I installed only a subset of what I wanted due to the really slow
dependency computation, and I figured I could add extra stuff
after I was up and running.

I can mount the DVD image, and I see it has a repodata directory,
so I created an /etc/yum.repos.d entry pointing to the DVD image,
and made it be the only repo enabled.

Unfortunately the Add/Remove software app doesn't find any of
the package group info that had things organized when installing.
It does find all the individual rpms, so I'm on the right track,
but where does it have to go to dig up the package groups?