Hi! The datasource file has its own deployment, so this file shall be put directly in the deploy folder. When doing this you'll see JBoss deploying the ds file. After the deloyment (takes a second or two) you can find the deployed datasource in the jmx-console (http://localhost:8080/jmx-console). In the jmx-console you shall be able to find a local transaction source, a connection pool etc. All these are are named from jndi-name in your ds.xml-file. The persitence.xml file shall be bundled in the classpath of the jar file containing your ejbs. The error you get must, as far as I can see, be due to an incorrect deployment of the ds-file. What if you only deploy the ds-file? Do get any errors? Can you see the deployed datasource in the jmx console? Best //Oskar View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4058103#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...