[rhelv6-list] Odd load average spikes

[Stephen John Smoogen]

On 18 December 2013 08:41, Chris Adams <linux at cmadams.net> wrote:

> I have a system that is a NAT/LVS front-end for a bunch of servers
> (mail, web, etc.).  I noticed in my monitoring that, about every 100
> minutes, the load average is spiking up to around 3-4 (not just a steady
> number, it fluctuates between maybe 2.5 and 4) for around 10 minutes.
> Then it drops back to near 0 fairly quickly.
>
>
It could be a number of processes hitting device wait at the same time.
Every process in device wait seems to increase the load average by 1. I
have seen servers with load averages of 100's running along fine but 100
processes stuck in device wait for a network connection or something and
not lowering the average. I would check to see when this happens what is in
D state.

The next two areas would be looking at iostat and sar during those times to
see what might be causing it to pop up.

Hope this helps.


-- 
Stephen J Smoogen.
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