How are you starting the app server? By manually executing run.bat or have you installed the app server as a service? If you installed the app server as a service, which utility did you use to do this? The utilities I know of include JBoss Native, JavaService, Java Service Wrapper and each configures JVM options differently. If you are using run.bat of JBoss Native the JVM heap options are set in JAVA_OPTS in run.bat. Have you used -verbose:gc (or other heap-monitoring options) to determine JVM heap usage? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4077461#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...