----- Original Message ---- > From: "fortin.pierre at bell.ca" <fortin.pierre at bell.ca> > To: centos at centos.org > Sent: Thu, January 14, 2010 5:47:43 PM > Subject: Re: [CentOS] High load since passing from rhas3 to centos4.8 > > > > The purpose of the server is to run NMS Telephony cards. The only support is for > Centos 4.x on 32 bit systems. Anyway, since I have not found the trouble, it may > still be there with another centos version. > > When I execute multiple ps during high load average period (above 10), here is > the kind of output I have: > > ps aux | grep " R" > USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND > root 16295 0.0 0.0 3492 772 pts/1 R+ 15:45 0:00 ps -aux > root 16296 0.0 0.0 5400 648 pts/1 S+ 15:45 0:00 grep R > > I see a lot of process in S, Sl, Ss+ and Ssl states. first of all, if you have high load average with seemingly low utilization, it may be because of load imbalance between CPUs and/or short bursts of lots of short cpu-intensive processes. Here's what I'd look at first: run "vmstat 1 10" and look at the first column. if it's higher than 1/ncpu you're having cpu saturation. rum "mpstat -P ALL 1 10", this gives you cpu utilisation per cpu (sar gives you the average among all processors) Also take a look at "sar -q 1 10" to look at the CPU's queues sizes Hope this helps Fer