Correct, I am planning to use a shared Solaris NFS drive to use as the shared filesystem. What I am trying to figure out is if I can reliably get optimistic locking to work between different nodes in a cluster. For example, we have optimistic locking enabled with the following situation: Node A gets a copy of the tree node and prepares to write some data into the cache. Meanwhile, Node B gets a copy also and writes its changes before Node A does. What I want to know, is what will Node A do? Will it fail/rollback? Can its internal version for the GlobalTransaction be smart enough to know that Node B wrote some changes before it. Any help would be appreciated. Ray View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4032566#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...