System Monitor is a utility designed to track various processes on a Windows 2000 system in real time, using a graphical display. You can use the data from System Monitor to target processes and components that need to be optimized, monitor the results of tuning and configuration efforts, understand and observe trends in workloads and their effect on resource usage, and assist with tasks such as planning for upgrades. System Monitor takes the form of an MMC snap-in. It is named Perfmon.msc and can be found in the %SystemRoot%\System32\ folder.
When you launch System Monitor from the Administrative Tools folder on the Programs menu, you see the main console (Figure 33-5). The console tree in the left pane lists the MMC snap-ins associated with System Monitor, and the details pane is reserved for the graphic view where the counters you want to monitor are charted.
Figure 33-5. The System Monitor console.
System Monitor uses three types of items to monitor the system: objects, counters, and instances:
By default, System Monitor displays the system's current processor utilization as a line graph. You can add counters by clicking Add Counters to display the Add Counters dialog box (Figure 33-6) or by clicking the Data tab in the Properties dialog box. System Monitor compresses the data as necessary to fit the details pane, and you can display dozens of counters at a time, more than you can comfortably view on a single screen.
Figure 33-6. The Add Counters dialog box.
In the Add Counters dialog box, you can select either the Use Local Computer Counters option or the Select Counters From Computer option. If you're monitoring the computer on which System Monitor is running, you'll want to select Use Local Computer Counters. If you want to monitor a different computer, select the Select Counters From Computer option, and then choose the name of the computer to be monitored from the list box.
In the Performance Object list box, specify an object to monitor. The Processor object is selected by default. For each object, you can choose to monitor all of the available counters or only those that you specify. To monitor all of the available counters for a particular object, select the All Counters option. To monitor only the counters you specify, select the Select Counters From List option. When you choose to select specific counters, you can obtain a description of any counter by selecting the name of the counter and then clicking Explain.
If you select a counter that has multiple instances, choose All Instances to monitor all instances of the selected counter, or choose Select Instances From List to specify the instances you want to monitor. If you monitor multiple instances of the same counter, you should be aware that the instance index number assigned to a particular instance might change over time. This possible change is a result of the instance starting and stopping and in the process being assigned a different instance index number.
You can determine which counter matches a line on the graph in two ways. First, a color and bar thickness is assigned to each counter within the legend. If you aren't monitoring many counters, you can easily match the color to the counter. Second, when you double-click a line in the graph, the corresponding counter is selected in the legend located under the graph. If chart lines are close together, try to locate a position in the graph where they diverge; otherwise, System Monitor will have difficulty pinpointing the actual line you're interested in.
You can also highlight a chart line by clicking the counter you want to highlight and then pressing Ctrl+H.
When you want to stop monitoring one or more counters, you have two options: you can delete only specific counters or you can delete all counters. To stop monitoring specific counters, open System Monitor, select the name of a counter in the legend in the System Monitor details pane, and click the Delete button on the toolbar. To delete all of the counters currently being monitored, click the New Counter Set button on the toolbar. You would do this if you wanted to start monitoring a new set of counters.
You can change the way System Monitor displays information by using the System Monitor Properties dialog box (Figure 33-7). To access this dialog box, either click the Properties button on the toolbar or right-click in the details pane and choose Properties from the shortcut menu.
Figure 33-7. The System Monitor Properties dialog box.
In the General tab, you can choose whether to view the data in the form of a graph, a histogram, or a report:
Figure 33-8. Displaying system information in graph view.
Although the graph view is the most versatile, you are better off using the histogram view or report view for tracking a large number of counters because the chart lines become increasingly difficult to view when a large number of counters are being monitored.
Figure 33-9. Displaying system information in histogram view.
Figure 33-10. Viewing system information in report view.
Depending on how you choose to view the data, these options in the Display Elements area might also be available:
You can sample data for all three views at regular periodic intervals. To set this option, open the System Monitor Properties dialog box (by clicking the Properties button on the toolbar) and, in the General tab, select the Update Automatically Every n Seconds check box. The default interval is 1 second, but you might want to change this value to prevent a strain on your machine. Select the update interval that is best for capturing the type of activity you want to view.
You can add vertical and horizontal grid lines to the graph and histogram views by selecting their respective check boxes in the Graph tab of the System Monitor Properties dialog box. These elements are very helpful in quickly determining a counter's associated value.
You can also change the maximum and minimum vertical scale values in the Graph tab; the defaults are 100 for the maximum value and 0 for the minimum value. The highest value that you can specify is 999999999, and the lowest value is 0. Both of these values must be a positive integer. You need to determine the vertical scale range from the ranges of values for the counters you are monitoring.
You might need to adjust the counter scale settings for a specific counter to improve the visibility of its data within the graph. Counter scale settings for individual counters are adjusted in the Data tab of the System Monitor Properties dialog box. Counter scale values can range exponentially from 0.0000001 to 1000000.0. Adjusting the scale does not affect the statistics displayed in the value bar.
By default, System Monitor displays information about the local system, but you can also configure it to monitor another computer on the network. It is also possible for you to monitor more than one computer at once in System Monitor. To do so, click Add Counters, select the Select Counters From Computer option, and then type the name of the computer to be monitored in the text box. You can choose and delete counters and modify the display in the same manner described in the previous sections.
You need administrative permissions on the other computer to monitor that computer through System Monitor. If you don't have administrative permissions, an error message is generated. The counter appears in the display, but no data or graph lines are associated with it. If a particular counter that you want to monitor does not appear in the counter list, it is likely that the service or feature providing the counter has not been installed or enabled on that computer.