The Recovery Storage Groups (RSG) feature was introduced with Exchange Server 2003 SP1. For restoring a mailbox in any previous version of Exchange Server, you had to create a separate forest with an Exchange recovery server and restore to the same server. After finishing with this, you were able to export the mailbox to a PST and then import the PST into your production mailbox.
The RSG is a feature for Exchange administrators. This advanced functionality allows administrators to mount a restored copy of a database on any server in the same Administrative Group. After the restoration is finished, you can begin to restore mailboxes in the database to your production server. You have the choice to restore a single mailbox, multiple mailboxes, or the entire database.
  • The process of recover Exchange mailboxes using ‘Recovery Storage Group’ comprises three main steps: Create a Recovery Storage Group
  • Restore your mailbox store to the Recovery Storage Group
  • Merge the restored mailboxes with regular user mailboxes in your production database
I. Setting up a Recovery Storage Group (For Windows Operating Systems other than Windows 2000 Server)
  • Go to ‘Start’-> ‘All Programs’-> ‘Microsoft Exchange’-> ‘System Manager’. This will launch Exchange System Manager.
  • Click on ‘Administrative Groups’ and choose the appropriate administrative group. Click on ‘Servers’, right-click the server on which you need to create the Recovery Storage Group, select ‘New’ and then click ‘Recovery Storage Group’.
  • Check ‘Recovery Storage Group Properties’ to verify the file locations listed in the Transaction log location box and the System path location. After completing the process, you will see the new Recovery Storage Group in the list of storage groups on the server.
  • Right-click ‘Recovery Storage Group’ and select ‘Add Database to Recover’.
  • In ‘Select Mailbox to Recover’, choose the desired mailbox store and click ‘OK’. You can select a single mailbox at a time.
  • Verify the properties of the chosen mailbox store. Keep the default settings as they are recommended.
  • You can add more mailboxes to the Recovery Storage Group in a similar way. In case you wish to restore multiple databases simultaneously, they should belong to the same storage group.
II. Restoring Mailbox Store to the Recovery Storage Group
  • Once the Recovery Storage Group is configured, you should start the backup and restore application of Windows, i.e. NTBackup.
  • Get to the ‘Advanced Mode’, if the application starts in ‘Wizard mode’.
  • Select ‘Restore and Manage Media’, click on ‘File List’, choose the backup file to be used and then select the appropriate storage group, database, and log files.
  • Click ‘Start Restore’. Specify the name of a temporary file directory in the ‘Restoring Database Store’ window. Select ‘Last Restore Set’, if the backup you are restoring is the last one to be restored.
  • When the process is finished, click ‘Restore’ and then ‘Close’.
  • Mount the mailbox store in the Recovery Storage Group in your Exchange System Manager. Click ‘Yes’ when a warning message appears.
III. Merging the Recovered Mailbox with Regular User Mailboxes in the Production Database 
  • Open Exmerge by typing ‘%path%\exmerge’ at the command prompt and then pressing ENTER.
  • Select the export method, the source server, and the destination server.
  • Choose the mailbox stores within the Recovery Storage Group on the Database Selection page and click ‘Next’.
  • Provide a suitable locale and then click ‘Next’.
  • Go to the ‘Target Directory’ page, click ‘Change Folder’, specify a temporary folder, and click ‘OK’. Click ‘Next’.
  • Follow the instructions in the wizard to complete the process of moving mailbox data.
When the process is finished, the wizard will copy all data in mailboxes within the restored mailbox store and merge it with the corresponding mailboxes in the original mailbox store.