[CentOS] Load Average ~0.40 when idle

Sat Jul 19 22:14:58 UTC 2008
listmail <listmail at entertech.com>

On Sat, 19 Jul 2008 14:50:18 -0700, listmail wrote
> On Sat, 19 Jul 2008 13:58:15 -0700 (PDT), Mark Pryor wrote
> > --- On Sat, 7/19/08, listmail <listmail at entertech.com> wrote:
> > 
> > > From: listmail <listmail at entertech.com>
> > > Subject: [CentOS] Load Average ~0.40 when idle
> > > To: "CentOS mailing list" <centos at centos.org>
> > > Date: Saturday, July 19, 2008, 1:48 PM
> > > I am running CentOS 5 on a dual-dual-core Intel machine, and
> > > I am seeing
> > > a load average of between 0.35 and 0.50 while the machine
> > > is idle, i.e.
> > > no processes appear to be running.
> > > 
> > > Both top and uptime report the same thing. Looking at top,
> > > I cannot see 
> > > any processes that are using CPU time except for top and
> > > init, and they are
> > > not using enough cycles to push up the load average.
> > > 
> > > According to top, there are occasional tiny (like 0.5%)
> > > bumps in the
> > > system usage occasionally, and almost no user space usage.
> > > Again, not
> > > enough to account for the load average I am seeing.
> > > 
> > > I have tried a couple of kernel updates, and upgraded from
> > > CentOS 5.0 to 5.2,
> > > none of which make any difference.
> > > 
> > > Has anyone else seen this? And can anyone recommend a way
> > > to figure out
> > > what is causing the load average to be this high when the
> > > machine is idle?
> > 
> > I have not seen this with any C5. However I have moved all
> > /etc/cron.daily/prelink
> > /etc/cron.daily/makewhatis
> > 
> > to the weekly.
> > 
> > check /var/log/secure for dictionary attacks
> > 
> > check your /var/log/httpd/access_log for unusual PHP activity
> > 
> > check http://localhost/usage for the webalizer logs, where maybe something
> >    will standout.
> > 
> Thanks, Mark. I have done all of that. There was a dictionary attack 
> a few days ago, but there is no activity now. Since this is a new 
> machine that I am just burning in, I am tempted to reinstall from 
> scratch in case the machine somehow got hacked during burn-in. I 
> don't see any stuck processes, or any other clues. I have an 
> identical machine running a slightly older version of the kernel 
> (CentOS 5.0 - 2.6.18.53.1.14.el5) that does not exhibit this problem,
>  so I am a bit suspicious. Has anyone else noticed anything like this?
> 
Replying to my own post as a follow-up. I just checked another machine that
I am burning in with CentOS 5.2, and it has the same problem: load average
~0.4 when idle. Both of these machines have Supermicro X7DBN motherboards,
but one is running a single quad-core CPU (Intel Xeon) and the other is
running two dual-core CPUs (Intel Xeon). Anyone else seeing anything like
this?

Thanks,
--Bill