Sounds like you wrote a disklabel that said the disk was larger than it 
actually is. Thus newfs'ing the partition trys to talk to blocks that don't 
exist. Type 'disklabel -r' and compare its numbers with what you know about 
the drive.

--Chuck

At 08:16 PM 5/9/01 -0700, you wrote:
>When I run newfs directly from command line I see:
>
>sd0(si0:3:0):illegal request, data = 00 00 00 00 21 00 01 c0 00 01
>
>in addition to the earlier messages.  Sysinst apparently hid this one
>from me.
>
>Ian