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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:
Linux memory management
System clean up
Disk subsystem tuning
Kernel tuning using sysctl
Network optimization
This chapter has the following sections:
4.1, “Tuning principals” on page 92
4.2, “Installation considerations” on page 92
4.3, “Changing kernel parameters” on page 104
4.4, “Tuning the processor subsystem” on page 108
4.5, “Tuning the vm subsystem” on page 110
4.6, “Tuning the disk subsystem” on page 113
4.7, “Tuning the network subsystem” on page 125
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