If you have recently upgraded your SharePoint 2010 Farm , you would notice the following Health Analyzer Warning :
Within Central Admin Under Upgrad and Migration you would find the following messages.
If you have a farm of Web Front Ends and Application Servers , Start the configuration Wizard on your primary Application server and it will stop and wait for you to finish the same task on the other servers in the farm. Complete it and then come back to your primary App server to finish the upgrade process. A Reboot of the farm is also recommended.