This is a question that I see almost every week. Someone is deploying Exchange Server 2010 and is uncertain whether they need to install the RTM build first, and then update it with Service Pack 1.
How to automatically redistribute and rebalance Exchange Server 2016, 2013 or 2010 mailbox databases in a Database Availability Group.
When an Exchange Server 2010 Database Availability Group has been upgraded to Exchange 2010 SP1 you may encounter an error when adding or removing database copies on a DAG member.
Microsoft has released Exchange Server 2010 Service Pack 1. Organizations already running Exchange Server 2010 (RTM) can upgrade to Service Pack 1, however the upgrade must be planned out properly to ensure a successful outcome.