Diagnosing a slow running Unix server

[mandy]

When your UNIX® system runs slow, it is vital that you discover what the problem is as quickly as possible so you can get your system back into the normal operating mode. There are many causes for a slow system, but actually identifying the problem can be exceedingly difficult. In this article, study examples of how to identify and diagnose the cause of your slow running UNIX system to get your machine running properly again.

Causes of slow systems

There are many different potential causes of a slow system, but they can generally be slotted into the following areas:

    * Too many processes. Your system is merely running too many applications at the same time, or running a small number of very CPU-intensive operations. Either you are overloading the server, or there is a runaway process that is sapping your system resources.
    * Too much active memory. If your processes are using a lot of memory, then your system might be swapping a lot of pages in and out to disk and, that means, your system is spending more time swapping the memory than it is actually using it.
    * Hardware fault. Occasionally you will come across a hardware fault that causes slow downs. A bad network card, hard drive, or memory might result in your system spending a long time waiting for information.

To diagnose the problem, you need to use a number of available tools to examine your UNIX system.

full article: http://www-128.ibm.com/developerworks/ai...1QuickUnix