Noob Centos Admin wrote: > However, iostat reports much lower %user and $system compared to top > running at the same time so I'm not quite sure if I can rely on its > figures. > ... > iostat > Linux 2.6.18-128.1.16.el5xen 12/30/2009 > avg-cpu: %user %nice %system %iowait %steal %idle > 3.28 0.20 1.16 2.38 0.01 92.97 > iostat, if run with no parameters shows the average since reboot or statistics reset. run `iostat -x 5` to a) show details on all devices, and B) show 5 second samples. ignore the first output as thats average. the 2nd and beyond outputs represent 5 second samples. note, btw, 'load average' isn't CPU usage, its the number of processes that are waiting to run. a load average of 8 means there are 8 processes waiting to use system resources. this does include processes in iowait, but doesn't include processes that are sleeping on semaphores and such, so it can be quite a lot higher than the cpu workload.