I bumped into a former colleague down the street today, and he asked how to go about converting existing Perfmon data from .blg (binary) to a different format, such as CSV or into a SQL database. (Yes, thatâ€™s right. I run into people I havenâ€™t seen in weeks, and we talk about SQL Server. Thatâ€™s normal, right?)
Going off on a slight tangent, which format of Perfmon log should you use? The four choices are Binary (BLG), Tab Delimited, Comma Delimited, and SQL Database. Binary is useful for most purposes, but becomes harder to extract the data out if you want to run any other processing on it. Tab and Comma delimited have the benefit of being able to view the data in Excel (if you donâ€™t have too many counters), and graphing can be easier. SQL Database has the benefit of logging straight into a SQL database, and this allows you to write a query to process your Perfmon data. For example, you could create an hourly average, or pull out the date/times of peak loads. The drawback to using a SQL database is that itâ€™s not as lightweight â€“ you quickly store a lot of data in your database, and increase the load on your server.
A good compromise may be to log into binary format, and then use the relog.exe command line tool to convert the data into SQL or comma/tab delimited format (which can then be opened in Excel or bulk-loaded into a database).
Relog.exe is a simple tool â€“ it allows you to convert between Perfmon file formats, extract specific counters, or change the sample period. Thereâ€™s not really much to explain that isnâ€™t mentioned in the Technet article at http://technet.microsoft.com/en-us/library/bb490958.aspx