Recently I want to conduct stress test in servers and I encountered some issues about using performance monitor. Google doesn't help.

I started by running perfmon, added a new data collectior set under "Data Collector Sets"->"User Defined", then added a new data collector that contains these counters:
\Memory\Available Bytes
\Network Interface(*)\Bytes Total/sec
\PhysicalDisk(*)\Avg. Disk Queue Length
\Processor(_Total)\% Processor Time
\Processor Information\% Processor Time
\PhysicalDisk\% Idle Time
\LogicalDisk\% Idle Time
By the way, I found that there were a default counter named "Performance Counter" there, so I deleted it.

Then I scheduled the collector set to run for 3 minutes, and I set the "Restart the data collector set at limits" option for duration of 1 minute. After the collection, 3 folders are generated, namely something like "USER-PC_20120109-00000(1-3)". Problems happen when I view the report in "Reports"->"User Defined"->"Data Collector Set 1"->"USER-PC_20120109-00000(1-3)".

When I view "USER-PC_20120109-000001", 3 error windows popup one by one.
1st: Unable to add these counters: \Memory\Pages/sec, \PhysicalDisk(_Total)\Avg. Disk sec/Read, \PhysicalDisk(_Total)\Avg. Disk sec/Write
2nd: One or more of the selected counters are already present and won't be added again.
3rd: The following system error occurred when trying to complete this operation: The specified record was not found in the log file.
After I clicked "OK" for these 3 windows, I can view these counters in the lower pane:
\Processor(_Total)\% Processor Time
\PhysicalDisk(_Total)\Avg. Disk Queue Length
\Network Interface(...)\Bytes Total/sec
\Network Interface(...)\Bytes Total/sec
\Network Interface(...)\Bytes Total/sec
\Memory\Available Bytes

So, the 1st problem is, I didn't include these counters when I created the collector set: \Memory\Pages/sec, \PhysicalDisk(_Total)\Avg. Disk sec/Read, \PhysicalDisk(_Total)\Avg. Disk sec/Write. How come it pops up an error window saying these are unable to add?

Also, I included these counters, but they are missing: \PhysicalDisk\% Idle Time, \LogicalDisk\% Idle Time.

Then I view "USER-PC_20120109-000003" as report. There is a warning saying that:
Symptom: Missing Events in Event Log
Details: Investigate why 26% (27,337) events were lost during data collection. The settings for Event Tracing for Windows (ETW) maximum buffers and buffer size may not be optimal depending on which data sets are being collected.

Googling said that I can increase the ETW buffer sizes by creating a key at registry: HKCU\SOFTWARE\Microsoft\VisualStudio\10.0\VSPerf\Monitor\EtwConfig. But I am not sure I want to do this, since this sounds strange to me that such setting is related to Visual Studio 10.0.

Anyway, for those of you used Performance monitor, any ideas?