Logging xperf trace data to a separate disk rather than the disk under analysis

Question

Hi,

I have some questions about tracing disk IOs.  They are:

- I would like trace disk IOs on my c drive only and then dump the trace onto a different drive so that the dumping of the trace will not change the characteristic of the workload. How do I do that?

- To further reduce the potential of altering the workload characteristics itself, I am also considering to perform in-memory logging and then dump it to a different drive.  The example in MSDN to stop the tracing xperf.exe -flush, xperf.exe -stop does not give any hints on where I can specify the drive where I would like to dump the trace.

Thanks,

Answer 1

Hi Bill,

nice idea ! :).

For the first request you can use the optional filter-function "disknum". The trick is you need to build a whole trace first. And this trace you can "dump" with xperf -i. And this will allow you to use the "disknum" function --> the disk number which you want you can check with "diskpart.exe [ENTER] list volume". For more details please have a lok at the WPT online help (*.chm) with the search "The DiskIdleHistogram Action". (don't surprise for the idle)

For the second question I think the solution is quiet easy. If you like to save your performace trace you can use the following example
"xperf -d G:\PerfLogs\Mem.etl" --> this allow you to use any available drives or devices :).

If this help --> don't foget to marked as answered and vote if you like.

Best regards

Rainer 

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RPA