I'm about to make an iso fs for a CD, but I'd like to be able to mount
it and tripple check that everything is present and working before I
burn a CD.

I was expecting that vnconfig would be what I'm after, but vnconfig(8)
talks about wanting geometries or disktab entries.

If someone has the answer I'd appreciate it - I've only got access to
the CD writer for a couple of days.

--sjg