Monitoring the System

It is necessary to monitor resource usage on the system while it is running to see if any resource bottlenecks exist. The primary resource parameters of interest are CPU usage and memory usage.

You can check the CPU usage in a number of ways. There is a graphical tool called the System Monitor (you can launch it by selecting Main Menu>System Tools>System Monitor). The System Monitor tab in this application displays the CPU usage over time in a nice graphical format, as shown in Figure 2-41.

Aside from the CPU usage information, the System Monitor tab also provides information on usage of memory (RAM and swap) and mounted filesystems.

Note

Swap memory isn t actually memory in the conventional sense. It s disk space that the operating system uses to store information temporarily ”the operating system swaps data from RAM to the swap memory, as necessary. Hence, it functions as if it were extra RAM, and allows the operating system to handle programs and data that require more actual RAM than is installed on the machine. The amount of swap memory available is determined by the size of the swap partition created when installing the operating system.

Figure 2-41