The problem I have is I need to clear down the database as the CLI is staying it is full (2048 users) I have deleted all old users and rebooted the box but it will not clear the old users, is there a way to purge the database
You should be able to expand it to something bigger. On the controller go to Security, AAA, General. Increase this number, it will require a reboot. I'm not sure the maximum you can increase it to (could be controller dependent).