High Load and Low CPU & Memory

[Furnish, Trever G]

> sysstat is installed, but the spikes seem to be happening so quickly I
> can't get a read on it.  For instance, "top" is running and all of the
> sudden load average was 20, but cpu is 95% idle.

Hmmm.  The RHEL install of sar defaults to collection every 10 minutes,
which isn't frequent enough for my tastes.  Smoothes out the spikes too
much.

If you let 'vmstat 1' or 'vmstat 5' run, do you see spikes in the 'r' or
'b' columns?


> -----Original Message-----
> From: redhat-list-bounces at redhat.com [mailto:redhat-list-
> bounces at redhat.com] On Behalf Of Troy Knabe
> Sent: Monday, March 02, 2009 4:51 PM
> To: General Red Hat Linux discussion list
> Subject: Re: High Load and Low CPU & Memory
> 
> 
> On Mar 2, 2009, at 1:24 PM, Furnish, Trever G wrote:
> 
> > Do your iowait percentages go up in top?  Perhaps you have an
> > i/o-related problem.
> 
> No, %wa is 0%
> 
> >
> > Are your network cards running at the same duplex as your connected
> > switch ports?
> 
> Yes they are 1000 Full Duplex
> 
> >
> > Is kswapd busy (ie your system's thrashing) during the spikes?
> 
> No.
> 
> >
> > You might get useful records by installing the sysstat package and
> > then
> > configuring sar to run every minute, then using sar to report on the
> > collected data.
> >
> 
> sysstat is installed, but the spikes seem to be happening so quickly I
> can't get a read on it.  For instance, "top" is running and all of the
> sudden load average was 20, but cpu is 95% idle.
> 
> 
> >
> >
> >> -----Original Message-----
> >> From: redhat-list-bounces at redhat.com [mailto:redhat-list-
> >> bounces at redhat.com] On Behalf Of Troy Knabe
> >> Sent: Monday, March 02, 2009 4:05 PM
> >> To: Red Hat
> >> Subject: High Load and Low CPU & Memory
> >>
> >> I have some brand new servers with 2 - Dual Core Xeons 3.33 Ghz and
> >> 48Gb of RAM.  Intermittently they are spiking to high load averages
> >> 5+
> >> or sometimes even 10+ and the application (oracle application
> server)
> >> becomes unresponsive.  We are moving them from 2 - Dual Core
> Opterons
> >> 2.4 Ghz and 12GB of RAM, and never experienced this type of
> >> situation.  Can anyone give me some suggestions on where to start
> >> looking?
> >>
> >> I am using Kerberos/LDAP authentication/authorization for the new
> >> ones, but the ldap servers do not appear to be the issue.  The
> oracle
> >> user is local to each server.
> >>
> >> Thanks
> >> -Troy
> >>
> >>
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