The webserver scanner logs roll over after 5 mb and there are only 2 logs in the rotation. For long webserver scanner scans, log entries will get overwritten.
This KB will provide instructions on how to increase the size of the WebServerScanner.log and number of logs in rotation.
In the default section of the VontuWebServerScanner.cfg, please add the following parameters:
LogFileMaxSize=10000 (in kb)
The above will increase the logs to 10,000 KB (or 10 MB) and will create an indefinite amount of logs.
Note: Since there will be no log rotation be aware that a long scan can take up hard disk space. Make sure there are plenty of hard disk space.