Trouble updating service pack 3
This seemed to be a major issue to me until I performed the upgrade in my test lab.
The statement above is correct for standalone mailbox servers, which is expected.
These local files are excluded from service pack downloads to reduce download size and time.
I admit I was concerned when I read the release notes for Exchange 2010 SP3 that state: The database schema has been updated in Exchange 2010 SP3.
Microsoft has released Service Pack 3 for Exchange Server 2010.
This is a significant release that delivers some key functionality to customers such as support for Windows Server 2012, support for co-existence with Exchange Server 2013 CU1, and general bug fixes and security updates.
However for an Exchange 2010 Database Availability Group the upgrade process can be performed with no downtime following the normal process of moving active databases off DAG members while they are being updated.
You can use the standard process as demonstrated here: However, be aware that once a database has been made active on an Exchange 2010 SP3 member of the DAG, it can't be made active on a pre-SP3 DAG member again.