<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns="http://www.w3.org/TR/REC-html40"> <head> <meta http-equiv=Content-Type content="text/html; charset=us-ascii"> <meta name=Generator content="Microsoft Word 11 (filtered medium)">  <style>  </style> </head> <body lang=PT link=blue vlink=purple style='word-wrap: break-word;-khtml-nbsp-mode: space; -khtml-line-break: after-white-space'> <div class=Section1> <o:p> </o:p> <div> Thanks Derek for your explanation.<o:p></o:p> <o:p> </o:p> I still have some doubts and appreciate some clarification:<o:p></o:p> <o:p> </o:p> 1.The server in question has 2 CPUs. When Nagios invokes check_load, does it monitor both the CPUs and reports the combined load average ?<o:p></o:p> <o:p> </o:p> 2. What are the CRITICAL, WARNING and OK thresholds for Load Average ? I mean when does it launch a Critical state ?<o:p></o:p> <o:p> </o:p> Thnx again,<o:p></o:p> <o:p> </o:p> Sg<o:p></o:p> <o:p> </o:p> </div> <div> <div class=MsoNormal align=center style='text-align:center'> <hr size=2 width="100%" align=center tabindex=-1> </div> From: nagios-users-admin@lists.sourceforge.net [mailto:nagios-users-admin@lists.sourceforge.net] On Behalf Of Derek J. Balling Sent: quarta-feira, 10 de Maio de 2006 11:52 To: nagios-users@lists.sourceforge.net Subject: Re: [Nagios-users] Check_load<o:p></o:p> </div> <o:p> </o:p> <div> <o:p> </o:p> </div> <o:p> </o:p> <div> <div> On May 10, 2006, at 6:42 AM, Sandeep Narasimha Murthy wrote:<o:p></o:p> </div> <div> <o:p> </o:p> </div> <o:p></o:p> <div> Can anyone please provide a brief idea on how check_load works and on the data it provides. The data provided is in the format load average: 1.62, 1.67, 1.74, which doesn’t make a lot of sense. I googled on this and ended up getting even more confused.<O:P style="font-family: Courier New; font-size: 13.3333px; "></O:P><o:p></o:p> </div> <div> <o:p> </o:p> </div> <div> "load average" is the number of processes (average) in the wait state over a given period of time. For most UNIX machines, the periods are usually 1, 5 and 15 minutes. (e.g., in your example, in the past minute an average of 1.62 machines were waiting for a CPU, in the past five minutes, 1.67, and in the past 15 minutes, 1.74).<o:p></o:p> </div> <div> <o:p> </o:p> </div> <div> In the example you give, it would appear your machine is catching up, as the short-term averages are lower than the long-term averages, but it all depends on your applications that are running, what cycles they demand CPU on, etc., etc.<o:p></o:p> </div> <o:p></o:p> <div> The reason behind my question is that we are also using CACTI for monitoring the systems and it shows a 100% CPU load since last night while Nagios didn’t raise any alarm at all. I have to find out whether it was a false alarm or there is a problem with my Nagios setup ..<o:p></o:p> </div> <div> It's confusing to refer to "100% CPU load" since load isn't measured in percentage (at least not in this case, not usually). Referring to it as 100% CPU usage, or utilization, might be better.<o:p></o:p> </div> <div> <o:p> </o:p> </div> <div> For example, it's possible to have a CPU load of "0" and usage of 100%. How? If I've only got one process making use of CPU cycles, and it's getting 100% of the CPU. If there's nothing else waiting for CPU, the "load" will not be high, even though the usage (from the single running process) will be.<o:p></o:p> </div> <div> <o:p> </o:p> </div> </div> <div> In other words, CPU usage isn't necessarily as important as load is, although it certainly can be a factor in determining the cause of Load (because processes which are waiting on Disk I/O, or swap, also contribute to load).<o:p></o:p> </div> <div> <o:p> </o:p> </div> <div> Hope this helps.<o:p></o:p> </div> <div> <o:p> </o:p> </div> <div> Cheers,<o:p></o:p> </div> <div> D<o:p></o:p> </div> <div> <o:p> </o:p> </div> <o:p> </o:p> <div> <div> --<o:p></o:p> </div> <div style='min-height: 16px'> <o:p> </o:p> </div> <div> Derek J. Balling<o:p></o:p> </div> <div> Systems Administrator<o:p></o:p> </div> <div style='min-height: 16px'> Vassar College<o:p></o:p> </div> <div style='min-height: 16px'> 124 Raymond Ave<o:p></o:p> </div> <div style='min-height: 16px'> Box 13 - Computer Center 217<o:p></o:p> </div> <div style='min-height: 16px'> Poughkeepsie, NY 12604<o:p></o:p> </div> <div> (845) 437-7231<o:p></o:p> </div> <o:p></o:p> </div> <o:p> </o:p> </div> </body> </html>