The Recovery Storage Group (RSG) feature in Exchange Server 2003 and Exchange Server 2007 lets you to mount a second copy of an Exchange mailbox store on any Exchange server in the same Exchange Administrative Group as the original while the original store is still running and serving clients. This allows you to recover data from an older backup copy of the store without disturbing client access to current data. See your Microsoft Exchange documentation for instructions on creating the recovery storage group and adding the mailbox stores you want to restore to it.
After the RSG is created and one or more stores are added to it, you can restore online backup sets to it. Then you can use the version of the EXMerge utility in Exchange 2003 and Exchange 2007 to extract mailbox data from the stores into .PST files, and optionally merge the extracted data back into the online stores.
Following are requirements for restoring Exchange Server 2003 and Exchange Server 2007 data using the Recovery Storage Group (RSG):
Do not mount mailbox stores in the RSG before the restore. If you do mount the stores before the restore, then you must dismount them. Select the following option on the database property page in Exchange System Manager:
On the server that hosts the RSG, there must be a storage group with the same name as the original storage group for the data you are restoring. If no such storage group exists on the server, then you can use that name for the RSG when you create it.
The Active Directory topology of the Exchange system must be intact and in the same state it was in when the backup was made. You cannot restore mailbox stores that were deleted and recreated. In addition, you cannot recover mailboxes from stores if the mailboxes were deleted and purged from the system or moved to other servers or mailbox stores.
Only Exchange mailbox stores from Exchange 2000 Server with Service Pack 3 or later can be restored to the RSG. Restored mailbox stores are upgraded to the store version currently running on the RSG server.
When the RSG exists on a server, the mailbox stores that it contains are the only stores that can be restored on that server by default. Symantec recommends that you create the RSG only when you intend to recover data using it, and remove the RSG from the server after the data recovery is complete.