FAQ Search Today's Posts Mark Forums Read
» Video Reviews

» Linux Archive

Linux-archive is a website aiming to archive linux email lists and to make them easily accessible for linux users/developers.


» Sponsor

» Partners

» Sponsor

Go Back   Linux Archive > CentOS > CentOS

 
 
LinkBack Thread Tools
 
Old 07-19-2008, 08:48 PM
"listmail"
 
Default Load Average ~0.40 when idle

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?

Thanks,
--Bill
_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 07-19-2008, 08:58 PM
Mark Pryor
 
Default Load Average ~0.40 when idle

--- On Sat, 7/19/08, listmail <listmail@entertech.com> wrote:

> From: listmail <listmail@entertech.com>
> Subject: [CentOS] Load Average ~0.40 when idle
> To: "CentOS mailing list" <centos@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.

--
Mark



_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 07-19-2008, 09:50 PM
"listmail"
 
Default Load Average ~0.40 when idle

On Sat, 19 Jul 2008 13:58:15 -0700 (PDT), Mark Pryor wrote
> --- On Sat, 7/19/08, listmail <listmail@entertech.com> wrote:
>
> > From: listmail <listmail@entertech.com>
> > Subject: [CentOS] Load Average ~0.40 when idle
> > To: "CentOS mailing list" <centos@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?

Thanks,
--Bill


_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 07-19-2008, 10:14 PM
"listmail"
 
Default Load Average ~0.40 when idle

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@entertech.com> wrote:
> >
> > > From: listmail <listmail@entertech.com>
> > > Subject: [CentOS] Load Average ~0.40 when idle
> > > To: "CentOS mailing list" <centos@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
_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 07-19-2008, 10:21 PM
Johnny Hughes
 
Default Load Average ~0.40 when idle

listmail wrote:

<snip>

Are you running X ... how many processes (on average are running).

Running X and logged in with applets and such, I have this:
================================================== =========
top - 17:18:49 up 4:13, 3 users, load average: 0.15, 0.27, 0.32
Tasks: 153 total, 2 running, 149 sleeping, 0 stopped, 0 zombie
================================================== =========

_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 07-19-2008, 10:49 PM
"listmail"
 
Default Load Average ~0.40 when idle

On Sat, 19 Jul 2008 17:21:44 -0500, Johnny Hughes wrote
> listmail wrote:
>
> <snip>
>
> Are you running X ... how many processes (on average are running).
>
> Running X and logged in with applets and such, I have this:
> ================================================== =========
> top - 17:18:49 up 4:13, 3 users, load average: 0.15, 0.27, 0.32
> Tasks: 153 total, 2 running, 149 sleeping, 0 stopped, 0 zombie
> ================================================== =========
>
One is running X, the other is not. The one that is running X has the
same load average as the one that is not. A small number of processes
are running, but as I said they are not using any CPU time, according
to top.
===
_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 07-19-2008, 11:04 PM
Mark Pryor
 
Default Load Average ~0.40 when idle

> 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?

Do you have hyper-threading turned on in the bios?
What shows in
cat /proc/cpuinfo

do you have 2 virtual CPU's per core?

I would be bet that performance improves by turning hyper-threading off.

--
Mark



_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 07-19-2008, 11:27 PM
"listmail"
 
Default Load Average ~0.40 when idle

On Sat, 19 Jul 2008 16:04:17 -0700 (PDT), Mark Pryor wrote
> > 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?
>
> Do you have hyper-threading turned on in the bios?
>
No, the BIOS does not support hyperthreading.
> What shows in
> cat /proc/cpuinfo
>
This is an example for one of the four CPUS - they are all the same
except for the processor number:
===
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 15
model name : Intel(R) Xeon(R) CPU 5130 @ 2.00GHz
stepping : 6
cpu MHz : 2000.191
cache size : 4096 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 2
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca
cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm
constant_tsc pni monitor ds_cpl vmx tm2 cx16 xtpr lahf_lm
bogomips : 4001.80
===
>
> do you have 2 virtual CPU's per core?
>
Nope.

The systems are running at at 1KHz interrupt rate and doing about 20 context
switches per second while idle. But as I said, this does not cause the CPU
load average to move off of 0.00 on another almost identical machine.

Thx,
--Bill
_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 07-19-2008, 11:28 PM
Dan Halbert
 
Default Load Average ~0.40 when idle

listmail wrote:
>it has the same problem: load average 0.4 when idle.

If you disconnect or shut down the NIC(s), does that make any difference?
_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 
Old 07-19-2008, 11:54 PM
"listmail"
 
Default Load Average ~0.40 when idle

On Sat, 19 Jul 2008 19:28:55 -0400, Dan Halbert wrote
> listmail wrote:
> >it has the same problem: load average 0.4 when idle.
>
> If you disconnect or shut down the NIC(s), does that make any difference?
>
Good suggestion. Disconnecting the Ethernet cables from the NICs did not
make a difference. However, shutting down the interfaces (e.g ifdown eth0,
ifdown eth1) did cut the load average down to nothing (0.00).

So it wasn't actual traffic, but something that the interfaces were doing,
or something that was trying to talk to one or both of them.

Does this result suggest anything else?

Thx,
--Bill
_______________________________________________
CentOS mailing list
CentOS@centos.org
http://lists.centos.org/mailman/listinfo/centos
 

Thread Tools




All times are GMT. The time now is 11:06 AM.

VBulletin, Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Relevant URLs by vBSEO ©2007, Crawlability, Inc.
Copyright 2007 - 2008, www.linux-archive.org