Sample configuration for the rolling file appender.
<appender name="fileStatisticsAppender" type="log4net.Appender.RollingFileAppender">
<file value="EPiServerStatisticsLog.txt" />
<encoding value="ascii" />
<lockingModel value="MinimalLock" />
<appendToFile value="true" />
<rollingStyle value="Date" />
<layout type="log4net.Layout.PatternLayout">
<param name="ConversionPattern" value="%date|%message%n" />
</layout>
</appender>
Create the output
2010-01-19 14:32:21,392 ERROR [182] EPiServer.Global - Error during processing