There is a saying: prevention is better than cure. If we apply that to server administration, then we can understand how important performance monitoring is. Monitoring the server's performance helps to identify server problems at an early stage of development, and we can then take the necessary steps to prevent them from turning into costly problems, in terms of both time and business.
To have productive performance monitoring, a clear plan with the right tools is required. That also means setting up a metric by which performance monitoring will be measured. Such a metric needs baseline information. This will help to evaluate the actual performance of servers, determine when hardware and software upgrades are needed, and evaluate whether an upgraded system is working better than the previous one.