Server Management and Monitoring - MCTS Guide to Microsoft Windows Server 2008 Active Directory Configuration - page 532

Performance Monitor Performance Monitor, under the Monitoring Tools folder, uses
counters to track the performance of a variety of objects. Performance can be tracked in real time
or scheduled for later review and analysis. A counter is a value representing some aspect of an
object's performance. For example, disk drives have counters representing the percent of time the
disk is used for read operations and the number of disk requests waiting to be serviced, among
many others. There are counters for about almost every hardware and OS component on a
server, including, of course, directory services.
Performance Monitor can track counters with a line graph (the default), a histogram (bar
graph), or as raw data saved to a report. To use Performance Monitor in real-time mode, you
simply add counters to the selected graph or report. You can add as many counters as you like,
but as you can see in Figure 13-12, the display can get crowded. If you're tracking several coun-
ters and want to emphasize one in the display, click that counter at the bottom and click the
Highlight toolbar icon or press Ctrl+H.

Change
graph type

Highlight

Figure 13-12

Viewing counters in Performance Monitor

Performance Monitor has two modes. You can display counters in real time, or you can open
a saved performance log file and view data that has been captured over a period of time. To
create a performance log, you create a new data collector set or start a saved data collector set.
After the data collector set has finished running, you can view collected performance data in
Performance Monitor.

Collecting Baseline Performance Data Viewing performance data in real time is
helpful if you want to see the impact certain actions have on selected counters. For exam-
ple, you might want to see the effect Active Directory replication has on CPU and network