vCenter Database Pre-Upgrade Checker
The vCenter Database Pre-Upgrade Checker is a utility to use on your current vCenter Server database to reveal problems that could prevent the upgrade or affect the performance of your database after the upgrade. A KB article with details on the tool can be found at http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=2004286.