I removed the requirement for the fillerSize, as I have talked to Tim. Now we aways move to the next position just based on the alignment of the File. I have committed this work into this Branch: http://anonsvn.jboss.org/repos/messaging/branches/trunk_tmp_aio/ I still have some work to do, like refactoring on few tests that are dealing with record sizes (what will change when using AIO). And also, I've found some problem with reclaiming files. The counter doesn't work properly in some situation when the commit is sent to another file. I didn't fully understand the counting, but it looks like there is a problem on the ref count. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4143229#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...