it's not there, nor should it be. sparc* does not use fdisk.
That's what I had read, but my other Netra T1 running 4.6 has it - and I used it when configuring RAIDFrame (raid(4))...why is it there? - why did it work?
Now I'm giving softraid(4) a go and these instructions (http://jpiasetz.tumblr.com/post/483365684/software-raid-on-openbsd-using-softraid) start by using fdisk(8).
This is the first time I've ever had to drop to Shell during install, and so figured it was missing...
