FileAppender append="false" does not truncate the file on startup

[Sharath Gururaj]

        <File name="MyFile" fileName="app.log" append="false" >

            <PatternLayout pattern="%d{HH:mm:ss.SSS} %-5level %l - %msg%n"
/>

        </File>


I expect app.log to be truncated on my application startup.

This is not the case. It is never truncated. Please help


Thanks

Sharath