Failed Request Tracing error LOG FILE MAX SIZE TRUNCATE

As you’ve probably read in my post AppCmd introduction and examples, AppCmd is a very extensive tool to administer Windows Server IIS hosting environments. Therefore, now a bit more about a common error message you might get using Failed Request Tracing: LOG_FILE_MAX_SIZE_TRUNCATE.

FREB error LOG_FILE_MAX_SIZE_TRUNCATE

If you’ve set up a Failed Request Tracing – also known as “FREB” – for a website in IIS, and if you’ve configure FREB with verbose information, a common error message you’ll probably get is:

LOG_FILE_MAX_SIZE_TRUNCATE

The maximum size of an FREB log file, in IIS 7+, is 512 KB per default. Once that size is reached, the log file is cut off (truncated) and a message LOG_FILE_MAX_SIZE_TRUNCATE is logged.

Did you know you can easily increase the FREB log file size server wide? The following AppCmd.exe command doubles the size to 1024 KB, or 1 MB:

AppCmd.exe set config /section:sites
 -siteDefaults.traceFailedRequestsLogging.maxLogFileSizeKB:1024Code language: JavaScript (javascript)

Interesting detail: FREB was first called Failed Request Event Buffering, and this is why the acronym doesn’t match its name in Windows Server IIS.