[CentOS] problem with machine "freezing" for short periods

[Jerry Franz]

On 07/27/2012 07:23 AM, Vanhorn, Mike wrote:
>
> As a followup, I've determined that it is network related, but I'm still
> not sure what the problem is. I did go back to CentOS 5.2, but the problem
> still exists with that version, too.
>
> Basically, what seems to be happening is that the network freezes around
> 30 seconds, and then picks right back up. There are no errors in any logs
> that I can find, and process that are running locally and that only depend
> on local resources keep right on going and don't have a problem.
>
> I have tried using a different network card (as opposed to the one on the
> motherboard), but the problem happens with that, too. It almost has to be
> a configuration issue, or a BIOS settting, but I don't get it.
>

That sounds like a timeout of some kind. Do you have many (thousands per 
minute) of transient network connections in normal operation? If so, you 
might be running into the open file limits if you haven't bumped up the 
limits.

Look at /etc/security/limits.conf and try adding

*                -       nofile          64000

-- 
Benjamin Franz