[CentOS] Intel Xeon and hyperthreading

[Sam Drinkard]

Jim Perrin wrote:

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>> I'm attempting to squeeze every last bit of processing power out of this
>> machine, and would entertain suggestions on tuning if there happen to be
>> any types of tuning that would help.
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> For performance tuning, I usually start with the filesystem tweaks:
> mount ext3 noatime, and changing the commit time from 5 to 30

Jim,

    Would you mount all filesystems noatime, or just those that would 
have any effect on operation?  I'm almost positive, there are things in 
one directory that are accessed very often, as well as written to every 
few seconds.  After reading about noatime, I'm not so positive it would 
help, altho I'm willing to give it a try.  Here's what I was reading 
from... http://www.faqs.org/docs/securing/chap6sec73.html

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> After that I move to /etc/sysctl.conf and tweak the kernel.shmmax,
> shmmin, shmall, and vdso values depending on the application I'm most
> concerned about, as well as fs.file-max.

Any hints on what to look for to determine the best settings?

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>> From there I move to the I/O scheduler/elevator for the system. RH
>
> magazine had a decent article about this.
> http://www.redhat.com/magazine/008jun05/features/schedulers/

According to that article, I might be better off staying with the CFQ, 
but since this is a number crunching thing, I really don't know what to 
look for, or where to look to see what really is going on behind the 
monitor.  I'm not savvy enough to know what the numerical model really 
does in the background is what I'm trying to say.  Any suggestions, or 
could I provide more info that might help you help me?

Thanks....

Sam

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-- 
Sam W.Drinkard -- sam at wa4phy.net
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