View the performance counters I have added to a Data Collector set after creation on Windows Server 2008 R2

You have created a Current View. As such, whenever you open a report in Performance Monitor it will attempt to add those performance counters to any log you open. If they already exist you'll receive this error message.

To fix this problem do the following

1. Open a saved report and clear the error messages
2. Right click on one of your performance counters select "Remove All Counters"
3. Hit OK when it asks if you are sure you want to remove all added counters
4. Click "Action"
5. Click "Save Current View"

Problem Fixed.

In my experience running data collector sets is safe, the main thing to keep an eye on is how much data you are generating. It really just depends on what you are looking for, but there are three ways to control how much data is collected:

1. The Number of counters you monitor
2. How long you let the collector run for
3. The "Sample Interval" the properties for the data collector (i.e. if you collect every 30 seconds, that is only 2 observations per minute.)

If you need a high resolution view of performance, you would be better off scheduling it every so often with a high sample interval. If you only need an aggregate overview of the day, you might want to go with something like one sample every few minutes. You can also set the maximum size of the data collected, but I would view that more as a safety net.

They can also be sent to SQL if you want to take off some of the data writing load. I believe choosing something like the binary format would take less space than something like csv.