That's a busy disk...
iostat -xnz 1on my desktop:
r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device
0.0 3.0 0.0 10.5 18444348816.8 18444348816.8 6148914691236.1 \
6148914691236.1 1844434881679 1844434881679 c1d0
Sorry if it wraps too much.
Of course, those numbers look very suspicious. I have seen this sort of silliness several times in iostat output recently though.