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Chapter 3. Bandwidth and Processing Power

3.2.3.1.1. Reducing Operating System Overhead

In order to reduce operating system overhead, you must look at your current system load and deter 

mine what aspects of it result in inordinate amounts of overhead. These areas could include:

Reducing the need for frequent process scheduling

Lowering the amount of I/O performed

Do not expect miracles; in a reasonably well configured system, it is unlikely that you will see much

of a performance increase by trying to reduce operating system overhead. This is due to the fact

that a reasonably well configured system will, by definition, result in a minimal amount of overhead.

However, if your system is running with too little RAM for instance, you may be able to reduce

overhead by alleviating the RAM shortage.

3.2.3.1.2. Reducing Application Overhead

Reducing application overhead means making sure that the application has everything it needs to

run well. Some applications exhibit wildly different behaviors under different environments   an

application may become highly compute bound while processing certain types of data, but not others.

The point to keep in mind here is that you must understand the applications running on your system

if you are to enable them to run as efficiently as possible. Often this entails working with your users,

and/or your organization's developers, to help uncover ways in which the applications can be made to

run more efficiently.

3.2.3.1.3. Eliminating Applications Entirely

Depending on your organization, this approach might not be available to you, as it often is not a

system administrator's responsibility to dictate which applications will and will not be run. However,

if you can identify any applications that are known "CPU hogs", you might be able to influence the

powers that be to retire them.

Doing this will likely involve more than just yourself. The affected users should certainly be a part

of this process; in many cases they may have the knowledge and the political power to make the

necessary changes to the application lineup.

Tip

Keep in mind that an application may not need to be eliminated from every system in your organiza 

tion. You might be able to move a particularly CPU hungry application from an overloaded system to

another system that is nearly idle.

3.2.3.2. Increasing the Capacity

Of course, if it is not possible to reduce the demand for processing power, you must find ways of

increasing the processing power that is available. To do so costs money, but it can be done.