Problem
You have an existing DAG cluster at a datacenter and have deployed another mailbox server at another DR datacenter to add to the DAG cluster. The configuration of the new mailbox database is in place and you are able to successfully add the node to the existing DAG. You proceed to create a test mailbox database at your production datacenter, successfully mount it but you receive the following error when you attempt to add a mailbox database copy to the DR mailbox server:
A source-side operation failed. Error An error occurred while performing the seed operation. Error: The NetworkManager has not yet been initialized. Check the event logs to determine the cause. [Database: <database name>, Server: yourServerName.com
You may also get the following error if you adding a mailbox database copy again:
A source-side operation failed. Error An error occurred while performing the seed operation. Error: Couldn’t seed the mailbox database copy because it is not suspended. Please suspend the mailbox database copy, and then retry the seed operation. [Database: <database name>, Server: yourServerName.com
Solution
While there are various reasons why this error would be thrown (i.e. misconfigured MAPI and replication networks), one of the common reasons I’ve come across is that Active Directory replication hasn’t happened yet between the 2 datacenters since they are in different sites. I’ve found that this issue is fixed when I ask the person calling me to force replication between the DCs in the 2 sites. The following is a screenshot of what the confirmation looks like when a mailbox database copy is successfully added:
