While running the psconfig got the following error:
An exception of type Microsoft.SharePoint.Administration.SPUpdatedConcurrencyException was thrown. Additional exception information: An update conflict has occurred, and you must re-try this action. The object SPUpgradeSession Name=Upgrade-20120310-130057-953 was updated by XXXX\svcSP_Farm, in the PSCONFIG (5168) process, on machine APP01. View the tracing log for more information about the conflict.
This issue occurs because a lock exists on the SPFarm object. Therefore, the SharePoint Products and Technologies Configuration Wizard cannot update the databases.
Cleared the SharePoint Services configuration cache.
For more information about how to do this, click the following article number to view the article in the Microsoft Knowledge Base:
939308 (http://support.microsoft.com/kb/939308/ ) Error message when you try to modify or to delete an alternate access mapping in Windows SharePoint Services 3.0: "An update conflict has occurred, and you must re-try this action"
You can also Ignore this lock by running the following command which will skip the lock step and proceed with the upgrade:
stsadm -o setproperty -pn command-line-upgrade-running -pv No