Re: [PLUG] high load average

[Bill Jonas <bill@billjonas.com>]

On Mon, Mar 05, 2001 at 09:15:50PM -0500, MaD dUCK wrote:
> the load average displayed by uptime has been very consistently above
> 2.00 and the output of ps aux has been pretty much the same for the
> past two weeks. no hung jobs. no traffic. the server basically *isn't
> being used*, especially not during the last 1, 5, or 15 minutes. and
> cron isn't running, there are *only* 35 running jobs. why, oh why then
> is it 200% loaded???

Sorry to be replying a little late, but I'm catching up on some of my
email.

The way that load average was explained to me was that it was the number
of processes waiting for time, per second.  I could be mistaken about
that, though.

And it's totally possible to have insane load averages.  On a couple of
machines here at home, I've gotten 60-80, possibly over 100-120.  Of
course, this was on purpose; I was trying to drive the load average up and
sustain it for a few minutes for torture test purposes.[1]  I've also seen
it "in the wild"; in the middle of last fall, I logged into a client's
machine (sysadminning), noticed that the machine was sluggish, and
discovered in short order that the load was 50-60 and climbing.  (It was a
bunch of runaway Mailman processes, but we think that it was due to a bad
couple of bits in the RAM.)  Later on, the machine was around 70-80,
before it died.

What was the point of the thread again?  Oh yeah.  I've noticed that a
rogue Netscape thread/process will take my load average to right at 1.00.
(This only occasionally happens, and is usually after Netscape crashes or
becomes lame.)  Killing the process solves the problem, of course.  I'm
not sure what process might be affecting you.  I'd suggest watching top(1)
for a few minutes.

[1] # $ while :; do find / -name '*' |xargs md5sum >/dev/null 2>&1 & done
Then, to read the load average when things get *really* sluggish, or you
get a process creation error, use:  $ read i </proc/loadavg; echo $i

-- 
Bill Jonas                | "In contrast to the What You See Is What You
bill@billjonas.com        |  Get (WYSIWYG) philosophy, UNIX is the You
http://www.billjonas.com/ |  Asked For It, You Got It operating system."
http://www.debian.org/    |  --Scott Lee, as quoted by Lamb and Robbins


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