NetBSD Mailing list wrote:
> I can access partition c just fine on my newly labelled
> SCSI drive.  I can't access any other partition.
> I can dd, newfs, etc... on /dev/rsd0c.   Accessing any
> other partition returns:
> 
> # newfs /dev/rsd0a
> newfs: /dev/rsd0a: open: Device not configured
> 
> 8 partitions:
> #        size   offset     fstype   [fsize bsize   cpg]
>   a:    15884        0     unused     1024  8192         # (Cyl.    0 - 14*)

I also stumbled over this one initially. You have to enter the filesystem 
type into the "fstype" field. Run "disklabel -e /dev/[yourdrive]" and edit
it. a: would be 4.2BSD, b: would be swap, d: is 4.2BSD, and so on. After
writing the disklabel you can newfs the 4.2BSD partitions.

Wolfgang