Newbie - Identifying IO bottlenick with systat. How to make sense of these numbers?

[Andres Salazar]

Hello..

Iam trying to use systat for identifying if when my applications/db
runs there is an IO bottleneck. Linux systat shows more info and it
seems there are more examples on the net.. but even though with  BSDs
iostat i dont know how to make sense of all these numbers.

I ran it this way:

systat iostat

   2 users    Load 1.94 1.06 0.68                      Mon Mar 22 11:57:16 2010

DEVICE               READ    WRITE     RTPS     WTPS      SEC
           STATS
sd0               6786252  8530739      138      521      0.6
     11839 numbufs
cd0                     0        0        0        0      0.0
     11828 freebufs
Totals            6786252  8530739      138      521      0.6
     47350 numbufpages

         0 numfreepages

        96 numdirtypages

     47210 numcleanpages

       -17 pendingwrites

         0 pendingreads

      2611 numwrites

      2532 numreads

     22564 cachehits

Basically my biggest concern is that whenever I do a mysqldump all
other queries are queued and mysql just gets waay slow.


Also.. this Hard disk is marked as 30Gb/sec (384 megabytes / sec) ..
Is it possible to saturate my HD  IO and view the traffic /megabyte to
see what is the maximum i can achieve?

Thanks...

Andres