I have recently re-created the User Profile Service application on a SharePoint 2010 farm to resolve issues with profile synchronization that occurred. In the process the existing ProfileDB and SocialDB were retained and FIM's SyncDB dropped to be created a fresh.
Original problems with profile sync are resolved but now see in Synchronization Service Manager the Management Agent of type "Extensible Connectivity" reports many discovery errors "need-full-object" for users.
The only event in Windows Event Log for FIMSynchronizationService is a warning
"...The rules configuration has changed since the last full import or full synchronization.
User Action
To ensure the updated rules are applied to all objects, a run with step type of full import and full synchronization should be completed."
A full synchronization is being run.
The synchronization runs for 12 hours+ before being shutdown by the farm backup process. There are around 5000 users in Active Directory and a full sync used to take 5-6 hours.
What is the best way to resolve this?