Date: Thu, 08 Jul 1999 19:41:39 -0700 From: David Greenman <dg@root.com> To: "Andrew Johns" <A_Johns@TurnAround.com.au> Cc: "=?iso-8859-1?Q?Alejandro_Ram=EDrez?=" <ales@megared.net.mx>, freebsd-questions@FreeBSD.ORG Subject: Re: Uptime basics!!! Message-ID: <199907090241.TAA04489@implode.root.com> In-Reply-To: Your message of "Fri, 09 Jul 1999 11:50:04 %2B1000." <002201bec9ad$5d7d4ad0$4001a8c0@tasajohns.turnaround.com.au>
next in thread | previous in thread | raw e-mail | index | archive | help
>The load average figures are an indication of the number of processors >(ie:CPU's) that would be kept 100% busy by the current processes >(ie:programs) running on the machine. > >So, load average = 1 implies you've got a busy machine which is using >100% of it's CPU(s) (irrespective of how many CPU's you have). If the >load goes to 5.3, then you are running enough processes to keep 5 CPU's >100% busy and one more CPU at 30%. Uh, no, that is not what the load average means. The load average is a composite number that includes both runnable processes and processes that are blocked in a short term wait (usually disk I/O). This means that for machines that are doing heavy disk I/O, the load average could be quite high even when the CPU is 95% idle. On wcarchive, for example, the load average typically runs around 40-50 with 50% CPU idle time. This may sound high, but there are 38 disk drives on the machine, so although the drives are fairly busy, the I/O is spread out over all of them - keeping the interactive response time low and overall performance quite high. -DG David Greenman Co-founder/Principal Architect, The FreeBSD Project - http://www.freebsd.org Creator of high-performance Internet servers - http://www.terasolutions.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199907090241.TAA04489>