On Mon, 4 May 1998 18:23:00 -0400 (EDT),
"Capt. Avram Dorfman" <dorfman@pentagon.mil> wrote:
> 
>    probe(ncrscsi0:2:0): Medium error, data - 00 00 00 00 82 00 00 00 00

Sounds to me like your disk drive has developed some hardware
problems, possibly bad sectors in a critical area for FFS.

> What causes this, and is there any way to recover?

Would it be feasible to low-level-format the drive?  But no, there's
no guarantee that it will recover.

Ken