 | | | Meaning of 'load ' on Linux | Meaning of 'load ' on Linux 2005-06-16 - By Stephen J. Smoogen
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On 6/16/05, Benjamin Franz <snowhare@(protected)> wrote:
> On Thu, 16 Jun 2005, Mimmus wrote:
>
> > Hi,
> > recently I had a discussion with an Oracle guy apparently involved in kernel
> > tuning.
> > I had some issues of "high" load on a RH3 server due to the infamous problem
> > with U3 (if I remember...).
> > He said me that "load" on Linux (i.e. output of 'uptime' or 'top') has a
> > different meaning than in other Unixes. Under HP-UX, I was comfortable with
> > values under 2-2.5; he said that under Linux 10-12 is normal and that he saw
> > working servers with load even of 1000 (!) using Oracle 'custom' kernels.
> >
> > What do you think?
>
> I think he is full of it.
>
> I consider anything significantly higher than double the number of CPU's
> you have in the machine excessive. It means you don't have enough hardware
> to run whatever it is you are doing effectively. I've never seen a less
> than 4 CPU machine with a sustained load of 10-12 that was acceptable. It
> means you don't have enough of one or more of the following: CPU cycles,
> memory, I/O bandwidth.
>
> It is possible the Oracle's 'custom' kernels have something else going on,
> but for a 'stock' kernel a load of 1000 means your machine is probably in
> a death spiral.
>
> --
> Benjamin Franz
>
> Simple things should be simple, complex things should be possible.
> - Alan Kay
>
> --
> Taroon-list mailing list
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>
It all depends on what the load average is being jacked up on.
Processes that are in device wait will increase the load average by 1
each. We had a box that was 'purring' along in a back closet that had
a load average of 200. It turned out that there was a dead NFS mount
that every logwatch df would sit and wait on.. Any other process going
on would fly by without issues.
My guess for a box with a load average of 1000 that is sustained..
that it is some sort of ghost process that is just sitting in the
background trying to make children that access a D area. I would not
consider this to be a good situation.. but a box could be very usable
with that occurin.
--
Stephen J Smoogen.
CSIRT/Linux System Administrator
--
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