Yup (from above) doing this:

rhino# dd if=/dev/dsk/c0t1d0s0 bs=1 skip=0 count=1024
dd: /dev/dsk/c0t1d0s0: open: I/O error
rhino# dd if=/dev/dsk/c0t1d0s2 bs=1 skip=0 count=1024
dd: /dev/dsk/c0t1d0s2: open: I/O error

The same with /dev/rdsk result in the same error, and yes I am root...