To save the captured I/O Trace information automatically as soon as it is recorded, use file logging. If you enable file logging, the I/O Trace log file is written as soon as each call is recorded. This option is useful in debugging an application that causes the system to crash before you can save current captures, because you can open the log file after restarting the system to see which call caused the error.
Note To guarantee that the captured log file is complete during a crash, log an I/O Trace Capture file with Write to file as soon as possible selected.

To enable I/O Trace file logging:

  1. Select Tools»Options when capture is stopped.
  2. Place a checkmark in the Log to File checkbox on the Logging tab. In the Log file path text box, either type the path and name for the log file, or use the Browse button to select a location for the I/O Trace log file.
  3. Select the type of file to log. For most applications, an I/O Trace Capture file is the best option. A I/O Trace Capture file is a binary format that is the quickest to create, and it can be logged in a fail-safe manner if you select Write to file as soon as possible. Only I/O Trace can open and display I/O Trace Capture files, but you can export them to other formats after logging is completed. If other applications need the log output while I/O Trace is logging, log to a plain text file or comma-separated variable (CSV) file. These files are slower to create and lack much of the information stored in an I/O Trace Capture file. But they are logged during I/O Trace operation, and other applications processing the output can use them. However, I/O Trace cannot load these files.
  4. Select the method of file logging. If you select Allow I/O Trace to schedule writing (the default), the log file is written with each recorded API call and closed only when capture is stopped. This method of file logging is more efficient than selecting Write to file as soon as possible, but may not be secure during system crashes. Consequently, you should use this option only if the problem you are trying to debug does not cause a system crash. If you select Write to file as soon as possible, the log file is opened, written, and flushed with each recorded API call. When logging to an I/O Trace Capture file, this method of file logging is secure during system crashes, but is somewhat slow because of the overhead caused by repeatedly opening and closing the log file.
Note   Using file logging is likely to slow down all applications. In addition, if you are low on disk space, choosing this option could cause you to run out of disk space. To turn off file logging, uncheck the Log to File checkbox.

Limiting File Size

For information about limiting file size to avoid running out of disk space, refer to Limiting File Size in the Capture Options topic.