[oclug] TOP interpretation

[Brad Barnett]

man 'top' should help you, Oddsox.

It will clarify much below, and correct the "wait" statement below.

That is:

        wa  --  iowait
          Amount of time the CPU has been waiting for I/O to complete.

See more info in the docs, or put another way ... RTFM :P

On Fri, 26 Jun 2009 12:33:10 -0400
Damian Gerow <dgerow at afflictions.org> wrote:

> OddSox wrote:
> : Further to my last message, I'm trying to figure out the
> significance : of the various CPU numbers in TOP on my CentOS 5.x
> server... : 
> : > Cpu(s):  0.3%us,  0.0%sy,  0.0%ni, 99.7%id,  0.0%wa,  0.0%hi,
> 0.0%si,  0.0%st : 
> : 
> : What does 99.7%id mean?
> 
> %us = user
> %sy = system
> %ni = nice
> %id = idle
> %wa = wait
> %hi = ?
> %si = system interrupts?
> %st = ?
> 
> I've never seen those last three, but it's been a few years since I
> bothered with 'top' in Linux.  System performance is a notoriously
> difficult thing to measure and understand...
> 
> user = amount of time the system is running userland code
> system = amount of time the system is running kernel code
> nice = I've never really understood this one
> idle = amount of time the system is doing nothing
> wait = amount of time the system is waiting for available CPU cycles
> 
> Or something like that.
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