JBoss uses Log4j for its internal logging. It controls Log4j through the conf/log4j.xml file. This is a normal Log4j XML config file with one addition. A JBoss specific TRACE level.
To request the trace service add a category section to log4j.xml:
<category name="org.jboss.mx.loading">
<priority value="TRACE"
class="org.jboss.logging.XLevel"/>
</category>
You can also configure different File Appenders for different logging categories.