I have a very large database. How do I stop the upgrade wizard from creating backups for me?

The OpenX upgrade wizard (from v2.4 and above) will make a copy of every table that will be affected by the changes. If the upgrade wizard detects the file "/var/NOBACKUPS" then no tables will be backed up during upgrade.

Please note that although the new upgrade system backs up your database as required, this feature is no substitute for making a full backup of your system before upgrading!