Playing with RSG | Database Restore

This came across few days back when one of our production Exchange 2003 backend server went down due to hardware failure and was totaly dead.The Backup team was shortly in action to carry out the restore. The restore was done on the different server in a Recovery Storage Group (RSG).

Now the question is how to merge these mailboxes in RSG with the production ones... certainly direct merge was not possible as we didnt opt for Dialtone method as the production server was totaly dead and we didnt set up a new server to replace that one.

The one option was to to extract the mailboxes from RSG using Exmerge, delete the existing mailboxes of users and create new ones on another server, and then import that extracted mailboxes. But this is very time consuming.
However here's an another option to tweak the RSG to make it behave as the production store and move that mailboxes over.

The Recovery Storage Group is identified by the msExchRestore Attribute. The msExchRestore = TRUE property tells us if a database is a recovery database.
As such we cannot directly connect the mailbox from the RSG to user direcly. We have to modify this msExchRestore Attribute and make its value to Not Set so that it cannot be identified as RSG and we can connect the mailbox to the user.

The detailed steps are as follows:

1. Reset the MsExchRestore attribute on both the Recovery Storage Group, and the recovered mailbox store using Adsiedit:

Expand the Configuration Container node, and then browse the hierarchy to:
DC=Domain
DC=com
CN=Configuration
CN=Services
CN=Microsoft Exchange
CN=Administrative Groups
CN=Administrative Group Name
CN=Servers
CN=ExchangeServerName
CN=InformationStore
CN=Recovery Storage Group

Right click for Properties on the Recovery Storage Group, ensure that the checkbox for "Show Optional Attributes" is checked. Scroll down to the "MsExchRestore" attribute. Double-click the MsExchRestore attribute and check the Not Set parameter. Click OK, Apply, and OK to exit the properties pane.
Right click the "CN=MailBox Store(ServerName)" under the Recovery Storage Group, and select Properties. Ensure that the checkbox for "Show Optional Attributes" is checked. Scroll down to the "MsExchRestore" attribute. Double-click the MsExchRestore attribute and check the parameter. Click OK, Apply, and OK to exit the properties pane.
Close the AdsiEdit mmc

2. Now from the ADUC>Exchange Tasks, delete the mailboxes of the users that are in question.

3. In Exchange System Manager select the Recovery Storage Group, right click and select Refresh. Expand the Recovery Storage Group, then the mailbox store.

4. Select "Mailboxes" under the Mailbox Store, then right click the mailbox to be recovered, and select "Reconnect". The applet "Select a New User for this Mailbox" applet will appear. Enter the alias of the user you wish to associate with the recovered mailbox into the "Enter the Object Name to select" data entry field, the click "Check Name". The alias of the user should be resolved to the full display name. Click OK. You will see a pop-up stating "The operation has completed successfully".

5. Once its done for all the users, you can successfully move the mailboxes over to any of the servers.