At beginning I believed that ejb's methods always runned on the server machine.
Now I've verified that if you have a client application running on a different machine than jboss server, and this one recall a method of an ejb, and this method makes access to the local file system, the CLIENT machine file system is accessed, not the SERVER one !!!!!!
That is very strange for me, because I know that EJB is based on RMI, and with RMI the execution of remote methods is don on the server, not on the client side. Luigi Fonti