> We are migrating HP servers from RHAS3 to centos 4.8. Since, the load
> average is reaching really high values. Under usage we see loads of
> 15-20 instead of the 0.5-1.5 we were used to.
>
> I searched a lot for information on such an issue. Iostat, vmstat, top,
> ps. But I don't get significant hint.
>
> Cpu usage remains low, IO wait remains low, no disks are lagging, no
> swap usage.
>
> Are there some tool / other way to diagnose why the load average is
> high? Like which processes are waiting, where they are stuck. Are there
> calls to drivers or system process that are slow?
>I don't have an answer but out of curiosity, why would you move to a 4.x
>instead of 5.x now?
>
>You might be able to do some ps snapshots to see the process in R state,
>which is what the load average should be counting. That might be
>computed differently between the 2.4 and 2.6 kernels.
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.
--
Les Mikesell
lesmikesell at gmail.com
_______________________________________________
CentOS mailing list
CentOS at centos.org
http://lists.centos.org/mailman/listinfo/centos