At any given moment, there could be dozens, if not hundreds, of different things happening on your system. Each requires systems resources, which may not be sufficient for everything to have an equal share. As a result, resources must be shared. As different processes interact and go about their business, what resource a process has and the amount of that resource that it is allocated will vary. As a result, performance of different processes will vary as well. Sometimes the overall performance reaches a point that becomes unsatisfactory. The big question is, what is happening?
Users might be experiencing slow response times on the server and tell you to buy a faster CPU. I have seen many instances in which this was the case, and afterward, the poor administrator is once again under pressure because the situation hasn’t changed. Users still have slow response times. Sometimes the users tell the administrator to increase the speed on their terminal or install a faster network card. Obviously a 9600 terminal or 10 Mbit network card isn’t fast enough when they are doing large queries in the database, so a faster one will speed up the query, right?
Unfortunately, things are not that simple. Perhaps you, as the system administrator, understand that increasing the baud rate on the terminal or the CPU speed won’t do much to speed up large database queries, but you have a hard time convincing users of this. On the other hard, you might be like many administrators who, because you were “unlucky” enough to have worked with a computer before, was thrown into the position, as often is the case. What many of us take as “common knowledge,” you may have never experienced before.
The simplest solution is to hire a consultant who is familiar with your situation (hardware, software, usage, etc.) to evaluate your system and make changes. However, computer consultants can be like lawyers. They may charge enormous fees, talk in unfamiliar terms, and sometimes in the end, you still haven’t gained anything.
Not all computer consultants or lawyers are like that. It’s simply a matter of not understanding what they tell you. If you do not require that they speak in terms that you understand, you can end up getting taken to the cleaners.
If you feel you need a consultant, do two things. As with any other product, you must shop around. Keep in mind that the best consultant to get is not necessary the cheapest, just as the best one is not necessarily the most expensive. The second key aspect is to know enough about your system, at least, conceptually to understand what the consultant is saying.
In this section, I am going to combine many of the topics and issues I discussed previously to find out exactly what your system is doing at this moment. By knowing what the system is doing, you are in a better position to judge if it is doing what you expect it to do, plus you can make decisions about what could and/or should be changed. This knowledge also has a side benefit of helping you if you should need to call a consultant.
So, where do we start? Well, rather than defining a particular scenario and saying what you should do if it happened, lets talk about the programs and utilities in terms of what they tell you. Therefore, I am going start with general user activity and proceed to the specifics.