I was just running some tests with AIO enabled and I couldn't believe the performance of acknowledgements. I looked in the code and it seems that it's only waiting for completion for adds, not for updates or deletes - this means that acknowledgements effectively return ok before they are persisted to disk! Ouch. In AIO mode, need to wait for completions on updates and deletes not just adds! View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4150110#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...