IBM REDP-4285-00 User Manual

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© Copyright IBM Corp. 2007. All rights reserved.
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Draft Document for Review May 4, 2007 11:35 am
4285ch04.fm
Chapter 4.
Tuning the operating system
By its nature and heritage, the Linux distributions and the Linux kernel offer a variety of 
parameters and settings to let the Linux administrator tweak the system to maximize 
performance. As stated earlier in this redpaper, there sadly is no magic tuning knob that will 
improve systems performance for any application. The settings discussed in the following 
chapter will improve performance for certain hardware configurations and application layouts. 
The very same setting that improve performance for a web server scenario might have 
adverse impacts on the performance of a database system.
This chapter describes the steps you can take to tune Kernel 2.6 based Linux distributions. 
Since the current kernel 2.6 based distributions vary from kernel release 2.6.9 up to 2.6.19 (at 
the time of writing this redpaper) some tuning options might only apply to a specific kernel 
release. The objective is to describe the parameters that give you the most improvement in 
performance and offer basic understanding of the techniques that are used in Linux, 
including:
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Linux memory management
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System clean up
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Disk subsystem tuning
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Kernel tuning using sysctl
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Network optimization
This chapter has the following sections:
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