To redistribute Exchange databases so they are mounted on the Mailbox Server that holds the first activation preference, run the following:
1. Open up Exchange Management Shell
2. Change the directory to the Scripts folder located in the Exchange Install Directory;
Example: CD “C:Program FilesMicrosoftExchange ServerV14Scripts”
3. Run the following command:
.RedistributeActiveDatabases.ps1 -DagName <dagname> -BalanceDbsByActivationPreference –ShowFinalDatabaseDistribution –Confirm:$false
Note: To find the DagName, you can run the get-databaseavailabilitygroup powershell command to list your Dags.
Ex-Shell 