As stated earlier, a great deal of system administration
revolves around resources and their efficient use. By balancing
various resources against the people and programs that use those
resources, you waste less money and make your users as happy as
possible. However, this leaves two questions:
The purpose of this chapter is to enable you to answer these
questions by helping you to learn more about resources and how they
can be monitored.
Before you can monitor resources, you first have to know what
resources there are to monitor. All systems have the following
These resources are covered in more depth in the following
chapters. However, for the time being all you need to keep in mind
is that these resources have a direct impact on system performance,
and therefore, on your users' productivity and happiness.
At its simplest, resource monitoring is nothing more than
obtaining information concerning the utilization of one or more
However, it is rarely this simple. First, one must take into
account the resources to be monitored. Then it is necessary to
examine each system to be monitored, paying particular attention to
each system's situation.
The systems you monitor fall into one of two categories:
The system is currently experiencing performance problems at
least part of the time and you would like to improve its
The system is currently running well and you would like it to
stay that way.
The first category means you should monitor resources from a
system performance perspective, while the second category means you
should monitor system resources from a capacity planning
Because each perspective has its own unique requirements, the
following sections explore each category in more depth.