Here’s a few quick points I wanted to make regarding Lessons Learned from upgrading OpsMgr 2007 R2 to OpsMgr 2012.  These points will help streamline the upgrade process and help you to upgrde OpsMgr in an efficient manner.

Lessons learned outline:

·        Use ‘Run As Administrator’ on Setup.exe to initiate upgrade sequence
o   I noticed failures during upgrade if ‘Run As Administrator’ was not used
 
·        Recommendation to remove the Exchange 2010 Correlation Service prior to upgrade
 

·        Disable any Connectors during upgrade

·        Backup Encryption Key for RMS just in case

·        Ensure good SQL DB backups prior to upgrade

·        Verify that the Operational DB has more than 50% free space prior to upgrade (suggestion by MS)

·        Disable Notification Subscriptions (reduce noise during upgrade)

·        Remove Agents reporting to RMS (distributed environment)

·        Improve Upgrade performance by running FREEPROCCACHE SQL statement

o   http://technet.microsoft.com/en-us/library/hh205980.aspx

·        Post upgrade, clean up the Localizedtext and Publishmessage table

o   http://technet.microsoft.com/en-us/library/hh241300.aspx

·        Update Overrides

o   TechNet: “If you created any overrides for the Active Directory Integration rules, you must recreate them after the management group upgrade is complete. Delete the old override, and then create a new, matching override that targets the Active Directory Assignment Resource Pools.”