When some of the features of dynamic dataset expansion first came out (may have been the master dataset and perhaps some combination with other features like jumbos) there were problems. Are there still problems? Should I avoid dynamic dataset expansion? Just upgraded our Orbit backup software so we can use the option which allows us to keep the system up during the entire backup. Ran into some messages when the database logging was turned off during the backup. The Orbit folks told us that it is best to keep logging turned on. Okay, but we need to increase the capacity sometimes . . . so thus my need to use dynamic dataset expansion.