If you simply want to use MySQL (or any other RDMBS) provider you simply need to create the datasource for that provider. Replacing the DefaultDS datasource would be necessary if you wanted to replace the persistence mechanism used interally by JBoss for JMS and other services. So, to create a datasource the steps are usually straightforward: 1) Look in your <jboss-home/docs/examples/jca directory and see if there is a sample *-ds.xml for your database. If so, simply copy this file, replace the values with your specific values and place the file in the <jboss-home>/server/<server-config>/deploy directory. Note, any number of datasources can be specified in the *-ds.xml file so it is not limited to one file->onedatasource 2) If there is not an example, simply copy one of the example files and replace the values with those from your JDBC driver documentation. More on JDBC configuration can be found on the JCA part of our Wiki: http://wiki.jboss.org/wiki/Wiki.jsp?page=ConfigDataSources View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4016526#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...