[NTLUG:Discuss] what do the uptime load average numbers mean?

[Tom Woody]

On Mon, 27 Jan 2003 17:27:02 -0600
"Richard Geoffrion" <ntlug at rain4us.net> wrote:

> 17:18:56 up 171 days,  1:36,  4 users,  load average: 3.40, 3.21, 2.38
> 
> 
> In the above example, what do 3.40, 3.21, and 2.38 signify?  Is that
> CPU load or an overall precentage load?  If so, they system is running
> slower than it's 3% use can account for.

3.40 is the Load Average for the past 1 minute
3.21 is the Load Average for the past 5 minutes
2.38 is the Load Average for the past 15 minutes

quoted from a googled cached document
(http://216.239.53.100/search?q=cache:Ne78mFIzCukC:support.webwizards.n
et/uptime.shtml+uptime+load+average&hl=en&ie=UTF-8)

Load Average

On a single processor machine, a load of 1 is maximum efficient
utilization. Loads more than the number of processors mean the machine
is too heavily loaded. Any load numbers in the 2 or 3 range is an
indication of excessive CPU use and consequently poor performance. Load
average numbers should be in the decimal range, for example; .02 or .53.

Load average is the amount of load that the server's CPU is
experiencing. What creates load on a CPU? When a program is run i.e., a
search program, a shopping cart program, a request to upload a web
site's page to a browser, an email program etc.. When any of the
preceding scenarios occur, a load (or demand) is placed on the server's
CPU. Some processes are given a higher priority by the CPU i.e., if a
server is performing a search and a visiting web surfer happens to
request a web page from a site hosted on that same server, then the page
upload is given priority over the search. The search will slow down in
order to accommodate the page upload.

Relative to page uploads the CPU's load average is not as critical as
the pipeline to server. The pipeline is the connection from the server
to the backbone provider. Pipelines are designated as 0C3, DS3, T3, T1,
etc.. and are an indication of how much data can be transmitted in kilo
bytes per second. A heavily loaded CPU will usually be able to out
perform the pipeline.

The load average numbers of 0.28, 0.18, 0.22 are reflections of 1, 5 and
15 minute intervals respectively.

Numbers like this "3.30, 1.05, 0.96" are not as much a cause for alarm
as numbers like this "2.52, 2.56, 2.51". The second set of numbers show
consistent heavy demand on the processor. This consistent heavy load
will deny the web pages the priority they need to load quickly. The
first set of numbers is indicative of a single process or program (such
as a search) performing it's function and will likely end very soon.

-- 
Tom Woody

Don't throw your computer out the window, 
throw the Windows out of your computer!