Analyzing Disk I/O

     How to Monitor Disk throughput
           % iostat   5    2
              tty                     wd0                            sd0                        cpu
         tin     tout      sps    tps     msps      sps      tps     msps        us     ni   sy    id
          2         9         2       0       0.5          3         0      20.3          0      0     0    99
          1      252        0       0       0.0       614      40      16.9         27     0   14    59

   tty:  data related to terminals
   tin:  total number of chars input per second
   tout: total number of chars output per second
   sps:  sectors transfered per second
   tps:   total transfered per second (most inportant, should > 50)
   msps: milliseconds per seek

   Seeking is the most important factor affecting disk drive performance