CPU Utilization

[mousematt]

Hi I'm fairly new to running my own dedicated server and I'm getting an alert email sent to me everyday now advising me that my CPU is hitting 80% for over 30mins.

I'm running Fedora 3 and have fairly basic knowledge/understanding of Linux. What I really want to know is a few pointers as to where to start looking for the cause of this high utilization (and any other advise relating to this)

Thanks in advance.

 

[thedaver]

If you see it happening during certain periods of the day, it may be a cron scripted activity.

A way (amongst many) to see what's impacting your CPU usage is to use the 'top' command.
Once top is running, press "P" (capital P!) to view by CPU usage (or "R" for RAM, etc.) Use "Q" to quit 'top'

Any process that stays at the top (other than 'init') is a potential culprit.

D.E.R. Management - IT Project Management Consulting

http://www.dermanagement.com/

 

[dlpar]

You can use sar to determine when the CPU is bound.
Yous can use nmon to resolve determine why your CPU is bound.

http://www-941.haw.ibm.com/collaboration/wiki/display/WikiPtype/nmon

 

[nerbonne]

It's most likely going to be your statistics update scripts which will run around midnight to 2AM that are pegging your CPU usage. Look at the time that the emails are being sent, and then go see what cron job is scheduled for that time. Run the cron manually and see what happens.

If it's the stats scripts, not much you can do about it. More importantly, at 2AM, does it really matter?