I have only one configuration file for the logging system. I have commented all categories out, but the root one.

Code:
<appender name="LSDailyRolling" class="com.lightstreamer.log4j.RelativeFileAppenders$DailyRollingFileAppender">
		<param name="File" value="../logs/server.log" />
		<!-- <param name="Threshold" value="INFO" /> -->
		<param name="DatePattern" value="'.'yyyy-MM-dd" />
		<layout class="org.apache.log4j.PatternLayout">
			<param name="ConversionPattern" value="%d %-5p [%c] %m%n"/>
		</layout>
	</appender>
...
<root>
   	  	<level value="INFO"></level>
      	<appender-ref ref="LSDailyRolling"/>
      	<appender-ref ref="LSConsole"/>
   	</root>