Thank you for your help! It works this way! With these different jars I wanted to divide my application into different modues. If I have to create another application with different features I want to assemble these different modules in a new ear. In this case it's not easy to decide in which jar I have to place my persistence.xml. I created another ejb-jar named OpenJbs_EJB.jar now that only contains the persistence.xml with the jar-files to scan: | <?xml version="1.0" encoding="UTF-8"?> | <persistence version="1.0" xmlns="http://java.sun.com/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd"> | <persistence-unit name="jabusuite" transaction-type="JTA"> | <provider>org.hibernate.ejb.HibernatePersistence</provider> | <jta-data-source>java:/JaBuSuiteDS</jta-data-source> | <!--<exclude-unlisted-classes>false</exclude-unlisted-classes>--> | | <jar-file>../JbsCore.jar</jar-file> | <jar-file>../JbsCalendar.jar</jar-file> | | <properties> | <property name="hibernate.hbm2ddl.auto" value="update"/> | </properties> | </persistence-unit> | </persistence> | The application.xml: | <?xml version="1.0" encoding="UTF-8"?> | <application version="1.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/application_1_4.xsd"> | <display-name>OpenJbs_Server</display-name> | <module> | <ejb>JbsCore.jar</ejb> | </module> | <module> | <ejb>JbsCalendar.jar</ejb> | </module> | <module> | <ejb>OpenJbs_EJB.jar</ejb> | </module> | <module> | <web> | <web-uri>JaBuSuite_Webclient.war</web-uri> | <context-root>/JaBuSuite_Webclient</context-root> | </web> | </module> | </application> | This seems not to be a very clean solution to me because the OpenJbs_EJB.jar is just a dummy. Isn't it possible to put the persistence.xml elsewhere? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4143718#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...