• The active copy of the mailbox database must be mounted.
  
  
• The specified database must be a mailbox database. You can't use continuous replication for public folder databases. For public folder database availability, we recommend deploying multiple public folder databases and using public folder replication. For more information, see Understanding Public Folder Replication.
  
  
• The specified Mailbox server must not already host a copy of the specified mailbox database.
  
  
• The path for the specified mailbox database and its log files must be available on the specified Mailbox server.
  
  
• The server hosting the specified database and the server that will host the database copy must both be in the same database availability group (DAG). The DAG must also have quorum and be healthy.
  
  
• If you’re adding the second copy of a database (for example, creating the first passive copy of the database), circular logging must not be enabled for the specified mailbox database. If circular logging is enabled, you must first disable it. After the mailbox database copy has been added, circular logging can be enabled. After circular logging is enabled for a replicated mailbox database, continuous replication circular logging (CRCL) is used instead of JET circular logging. If you’re adding the third or subsequent copy of a database, CRCL can remain enabled. For information about how to enable and disable circular logging, see Configure Mailbox Database Properties.
  
  

• Use the EMC to add a mailbox database copy
  
  
• Use the Shell to add a mailbox database copy
  
  

You need to be assigned permissions before you can perform this procedure. To see what permissions you need, see the "Mailbox database copy" entry in the High Availability Permissions topic.

1. In the console tree, navigate to Organization Configuration > Mailbox.
   
   
2. In the result pane, on the Database Management tab, right-click the mailbox database that you want to copy, and then click Add Mailbox Database Copy.
   
   
3. On the Add Mailbox Database Copy page, complete the following fields.
   
   
   • Mailbox database name   This read-only box displays the name of the database for which you are going to make a copy.
     
     
   • Server name   Click Browse to open the Select Mailbox Server dialog box. Use this dialog box to select the Mailbox server that will host the copy of the mailbox database, and then click OK.
     
     

     Note:
     The Select Mailbox Server dialog displays all Mailbox servers. You must select a Mailbox server that it is in the same DAG as the Mailbox server hosting the active copy.

   • Activation preference number   Use this box to specify the activation preference number for the database copy. The activation preference number is used as part of Active Manager's best copy selection process and to redistribute active mailbox databases throughout the DAG when using the RedistributeActiveDatabases.ps1 script. The value for the activation preference is a number equal to or greater than 1, where 1 is at the top of the preference order. The position number cannot be larger than the number of copies of the mailbox database.
     
     
4. Click Add to add the copy of the mailbox database.
   
   
5. On the Completion page, review the following, and then click Finish to close the wizard:
   
   
   • A status of Completed indicates that the wizard completed the task successfully.
     
     
   • A status of Failed indicates that the task wasn't completed. If the task fails, review the summary for an explanation, and then click Back to make any configuration changes.
     
     
6. Click Finish to close the wizard.
   
   

You need to be assigned permissions before you can perform this procedure. To see what permissions you need, see the "Mailbox database copy" entry in the High Availability Permissions topic.

In this example, a copy of mailbox database DB1 is being added to a Mailbox server named MBX3. Replay lag time and truncation lag time are left at the default values of zero, and the activation preference is configured with a value of 2.

	Copy Code
Add-MailboxDatabaseCopy -Identity DB1 -MailboxServer MBX3 -ActivationPreference 2

In this example, a copy of mailbox database DB2 is being added to a Mailbox server named MBX4. Replay lag time and truncation lag time are left at the default values of zero, and the activation preference is configured with a value of 5. In addition, seeding is being postponed for this copy so that it can be seeded using a local source server instead of the current active database copy, which is geographically distant from MBX4.

	Copy Code
Add-MailboxDatabaseCopy -Identity DB2 -MailboxServer MBX4 -ActivationPreference 5 -SeedingPostponed

In this example, a copy of mailbox database DB3 is being added to a Mailbox server named MBX5. Replay lag time is set to 3 days, and truncation lag time is left at the default value of zero, and the activation preference is configured with a value of 4.

	Copy Code
Add-MailboxDatabaseCopy -Identity DB3 -MailboxServer MBX5 -ReplayLagTime 3.00:00:00 -ActivationPreference 4

Understanding Mailbox Database Copies

Managing Mailbox Database Copies