Leitura recomendada. Se você precisa ajustar alguma configuração do Linux, identificar algum gargalo no seu sistema, esse documento pode te ajudar. É o Redpaper da IBM Linux Performance and Tuning Guidelines, e um trecho do documento diz:

The use of Linux in an enterprise-class server requires monitoring performance and, when
necessary, tune the server to remove bottlenecks that affect users. This IBM Redpaper
publication describes the methods you can use to tune Linux, tools that you can use to
monitor and analyze server performance, and key tuning parameters for specific server
applications. The purpose of this paper is to explain how to analyze and tune the Linux
operating system to yield superior performance for any type of application you plan to run on
these systems.

Você pode baixá-lo aqui: http://www.redbooks.ibm.com/abstracts/redp4285.html?Open