vmstat
 

I am trying to determine if our application is IO bound and we are hitting disk seek bottleneck.

From my research,if the value in the last column (wa) in vmstat out put is high, then application is IO bound. what is this magically high number? if i constantly see value 2 in wa column, would it be a problem? or if i see double digits in wa column would be a problem?

Also, another website pointed out that first column (R) should preferably less then number of processors other wise it could be IO bound. On one machine i have seen this hit 13 few time sand that machine doesn't have 13 processors.

I am trying to get a ball park numbers that will help me either eliminate this problem from my trouble shooting list or delve deeper into this.

thanks
lucifer..

In my experience, if you see a %wait go above 20 for CPU usage, that usually indicates disk I/O issues. You might have better luck using something like nmon or iostat to determine the bottleneck.