"Christopher_P" wrote : However, one thing that I've not been able to find a definite answer to is how well EJB 2.x and EJB 3.0 entities coexist. Ah ha! Today's search was more fruitful: http://www.jboss.com/index.html?module=bb&op=viewtopic&t=72369. Bill Burke states that it is in fact dangerous to mix CMP and EJB 3.0 persistence. Not the answer I was hoping for but an answer nevertheless. The web still seems fairly thin on migration strategies from CMP to JPA/EJB 3.0 persistence. As it stands it seems like the only option is to migrate all entities at once (!). Any useful resources would be most welcome. Cheers, Chris Paton View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4102180#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...