glassfish-resources.xml is ignored during the deployment of a Java EE application. Environment: NetBeans 8.0.1 GlassFish 4.1 Java DB 10.10.2.0 - (1582446) Here is a procedure to reproduce the problem. 1. With Java DB (intalled in C:\Program Files\glassfish-4.1\javadb), I create a new database db1. 2. I create a Web Application with GF 4.1, without any framework. 3. In the project, New > Entity Class. I check "Create Persistence Unit". New Data Source jdbc/db1 with database connection to the database created in the first step. Table generation strategy: create. glassfish-resources.xml generated: persistence.xml generated: jdbc/db1 false 4. New session bean stateless. Sb1 Insert Code and Use entity manager. Code of the EJB: package ejb; import javax.ejb.Stateless; import javax.persistence.EntityManager; import javax.persistence.PersistenceContext; @Stateless public class Sb1 { @PersistenceContext(unitName = "TestPbDSPU") private EntityManager em; public void persist(Object object) { em.persist(object); } } 5. Deploy. Glassfish 4.1 starts. Problem: Grave: Exception while invoking class org.glassfish.persistence.jpa.JPADeployer prepare method Grave: java.lang.RuntimeException: Invalid resource : jdbc/db1__pm at com.sun.enterprise.connectors.ConnectorRuntime.lookupDataSourceInDAS(ConnectorRuntime.java:593) at com.sun.enterprise.connectors.ConnectorRuntime.lookupPMResource(ConnectorRuntime.java:517) at org.glassfish.persistence.common.PersistenceHelper.lookupPMResource(PersistenceHelper.java:63) at org.glassfish.persistence.jpa.ProviderContainerContractInfoBase.lookupDataSource(ProviderContainerContractInfoBase.java:71) at org.glassfish.persistence.jpa.PersistenceUnitInfoImpl.(PersistenceUnitInfoImpl.java:108) at org.glassfish.persistence.jpa.PersistenceUnitLoader.loadPU(PersistenceUnitLoader.java:142) at org.glassfish.persistence.jpa.PersistenceUnitLoader.(PersistenceUnitLoader.java:107) at org.glassfish.persistence.jpa.JPADeployer$1.visitPUD(JPADeployer.java:223) at org.glassfish.persistence.jpa.JPADeployer$PersistenceUnitDescriptorIterator.iteratePUDs(JPADeployer.java:510) at org.glassfish.persistence.jpa.JPADeployer.createEMFs(JPADeployer.java:230) at org.glassfish.persistence.jpa.JPADeployer.prepare(JPADeployer.java:168) at com.sun.enterprise.v3.server.ApplicationLifecycle.prepareModule(ApplicationLifecycle.java:925) at com.sun.enterprise.v3.server.ApplicationLifecycle.deploy(ApplicationLifecycle.java:434) at com.sun.enterprise.v3.server.ApplicationLifecycle.deploy(ApplicationLifecycle.java:219) at org.glassfish.deployment.admin.DeployCommand.execute(DeployCommand.java:491) at com.sun.enterprise.v3.admin.CommandRunnerImpl$2$1.run(CommandRunnerImpl.java:539) at com.sun.enterprise.v3.admin.CommandRunnerImpl$2$1.run(CommandRunnerImpl.java:535) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAs(Subject.java:360) ... 6. If I add the connection pool and the JDBC resource by asadmin, no problem with glassfish-resources.xml and no more problem with the deployment of the application because the JDBC resource is registered in the server. add-resources C:/Users/richard/Documents/NetBeansProjects/TestPbDS/setup/glassfish-resources.xml