In pursuit of an MCSA or MCSE, you will definitely encounter a question or two (possibly more) about System Monitor counters. Microsoft expects you to know some of the common counters used to establish a baseline of performance. You also need to know when the values for specific counters indicate a bottleneck. The common System Monitor counters that you need to be familiar with are outlined below:

Memory

• Pages/sec

• Available bytes

Processor

• % Total Processor Time - A continuously high value may indicate a bottleneck

• Processor Queue Length

Disk

• Logical Disk: % Free Space

• Logical Disk: % Disk Time - Over 50% indicates a bottleneck
• Physical Disk: Avg. Read Queue Length - Value should be lower than 2
• Physical Disk: Avg. Write Queue Length - Value should be lower than 2

Network

• Network Interface: Output Queue Length

• % network utilization

Now in the real world, remember to take these guidelines with a bit of salt. This doesn’t mean that you should disregard them, but it does mean that you need to look at every aspect of the situation and the server that’s available to you. This falls within the ‘diversity’ clause.

Personally, I have low blood pressure. My doctor says that this is not a problem, although it drives many friends and relatives nuts. There was once a time when I had to go to the doctor because I’d passed out, and my blood pressure was so low it wouldn’t register on the machine: according to the machine, I was actually dead. Although I’m happy to report I’m not, it’s due to good communication between doctor and patient that avoided an unnecessary trip to the bowels of the hospital and the untold price tag that would have come with it. Incidentally: normally such a low blood pressure indicates that a patient is going into shock, and doctors tend to do all sorts of scary things when that happens. The real ‘problem’: I was pregnant. The moral of the story: try to keep a good perspective between what Performance Monitor reports and what your conclusions are. No matter what: make sure that you’re absolutely positively sure about a conclusion before you do anything drastic.