[SunHELP] determine the reader or writer process

[sunhelp at sunhelp.org]

given the following:

iostat -n -M -D 2 5 (used from Dave Anjans post on sunmanagers)

   c0t0d0        c0t1d0        c0t6d0        c2t1d0     
rps wps util  rps wps util  rps wps util  rps wps util  
  0 181 69.1    0 181 79.8    0   0  0.0    0   0  0.0  
  0 168 75.5    0 167 72.3    0   0  0.0    0   0  0.0  
  0 163 55.1    0 163 80.3    0   0  0.0    0   0  0.0  
  0 165 53.8    0 165 82.9    0   0  0.0    0   0  0.0  
  0 168 58.2    0 167 82.4    0   0  0.0    0   0  0.0  

where do I start to determine which process would be 
causing these ~165 wps on c0t0d0?  i'm thinking it should
be swap but i'd like to know how to pinpoint for other scenerios.