Recipe11.11.Recovering to a Recovery Storage Group in Exchange Server 2003

Recipe 11.11. Recovering to a Recovery Storage Group in Exchange Server 2003

Problem

You need to restore a storage group from backup media or files.

Solution

Using a graphical user interface

Launch the Exchange System Manager.
Navigate to the server you will place the RSG on. Right-click, select New, and select RSG.
Set the name for the new RSG. If you are recovering from a storage group not already present on the server, you must set the name of the RSG to be the same as the name of the storage group you are recovering.
Provide the system path, as well as a path for the associated transaction logs. Make sure these locations have sufficient disk space and are not shared by other storage groups or transaction logs.
Right-click on the RSG and select Add a Database to Recover.
Select a database from those presented. If a database is already present in the RSG, you can only select other databases in the same storage group. Click OK.
Set the name for the database.
Provide paths and names for the database and streaming database files. These paths and names only need to match the original names if you are going to manually copy these files on top of the original database files after the recovery is complete.
When you are ready to perform the restore, ensure that the original databases are not mounted (see Recipes Recipe 11.4 and Recipe 11.5).
Ensure that you have set the This database can be overwritten by a restore option on all databases to be restored.
You can now begin the restore process as outlined in Recipes Recipe 11.4 and Recipe 11.5.
Once the online backups have been restored, use ExMerge to merge the restored data into the live databases, as described in the ExMerge documentation, included with the ExMerge download package.

Discussion

RSGs are an impressive new feature in Exchange Server 2003.

Once you install the Exchange Server 2003 System Manager or server components on a machine, the Exchange backup API DLLs are updated to provide support for the RSG. Any backup utility (including Ntbackup) that supports that API can automatically and transparently make use of the RSG capability. This, in turn, allows you to restore from backups without service interruptions, applying any transaction logs generated during the backup. If the database being restored is registered in the RSG, the API silently directs the restoration to the RSG.

One thing to note is that if the RSG is configured on a server, all restores on that server must take place through the RSG or they will abort. Removing the RSG will immediately cause the server to revert to pre-RSG behavior.

In testing situations, it is possible to override the RSG behavior without having to remove the configured RSG. Create a DWORD value named Recovery SG Override under this registry key on the Exchange Server:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeIS\ParametersSystem

When the value is set to 1, the Information Store will ignore the presence of the RSG; when set to 0, the RSG will work as normal. Changes to this value are picked up on the fly. If you use this feature, be sure to completely remove the Recovery SG Override value from the registry when you are done testing to avoid unintentional damage to production databases.

To recover data from a mailbox in the RSG, the mailbox must reside in the original database from which the database backup you are restoring was generated.

RSGs have some key limitations to remember:

AD must contain whole and unchanged configuration information about the storage groups and databases.
The recovered database must be on a server in the same administrative group as the server performing the restore.
Recovering single mailboxes and deleted items from mailboxes is possible as long as the mailboxes are in the same database, and are connected to the same user account (by GUID, not username), as they were when they were backed up.
You may only recover multiple databases simultaneously if they are all members of the same original storage group.
The recovered database must be from at least Exchange 2000 SP3, and cannot be from a version of Exchange Server 2003 (with service packs) newer than the machine performing the recovery. If the database is from an older version of Exchange, it will be converted to the native version of the recovery machine.
RSGs do not support recovery from public folders and cannot be used to restore entire servers.
All protocol access to RSGs is disabled, except for MAPI, and only the Exchange Server 2003 version of ExMerge is equipped to connect to and browse the contents of databases in the RSG. You will need to use ExMerge in order to merge recovered data back into your production mailbox databases; this can be done across machines.
Mailboxes in RSG databases are not connected to user accounts, nor are they subject to any policies, preventing the accidental deletion of restored data.