Changes to Backup and Restore in Exchange 2010
Microsoft Exchange Server 2010 introduces new technologies and features in many areas, and removes other important storage features. To implement Exchange 2010–compatible backup and restore applications, you may need to adjust your application to accommodate the changes described in this topic.
Exchange Storage Groups Removed
Exchange 2010 no longer includes the concept of storage groups. In earlier versions of Exchange, one or more Exchange store databases can be grouped into a storage group, which can then be managed as a unit. However, storage groups complicate many high-availability scenarios, and make single-database restores more complex.
Exchange 2010–compatible backup and restore applications that work with the Windows Volume Shadow Copy Service (VSS) no longer provide storage group identifiers in the VSS backup component paths. You can find more information about the new backup component path construction in the Backup Operations section of this SDK.
Recovery Storage Group Replaced with Recovery Database
Because storage groups were removed from Exchange Server 2010, the recovery storage group no longer exists. Instead, if your application needs to restore, recover, and mount an Exchange database to a different location or server, it will use a recovery database. The recovery database is not tied to any original server or database. Each Exchange 2010 server can have no more than one mounted recovery database. There can be multiple recovery databases, but only one can be mounted at a time. For more information, see the Restore and Recovery Operations section of this SDK.
Streaming Backups Not Supported
Exchange 2010 does not support streaming-style backups. In versions of Exchange earlier than Exchange 2010, backup applications use the ESEBCLI2 interface to perform streaming backups. This SDK does not contain information about the ESEBCLI2 DLL. For information about this interface, see ESEbcli2 DLL Functions Interface.
Number of Databases per Server Increased
In Exchange 2007, each server can mount 50 databases configured in up to 50 storage groups. In Exchange 2010, each Exchange server can connect to a maximum of 100 Exchange databases, and storage groups do not exist. Although each Exchange server can have a maximum of 100 databases mounted at one time, that limit does not apply to the total number of database objects that are stored in Active Directory Domain Services (AD DS). Each Exchange organization can have any number of database objects in AD DS.
For backup and restore applications, the maximum of 100 mounted databases for an Exchange organization includes up to one mounted recovery database. There is no distinction between normal and recovery databases in this maximum number.
Database Mobility and Availability Groups Added
Exchange 2010 servers can be configured to perform even more flexible database replication than Exchange 2007 servers. Each Exchange 2010 database can be replicated to up to 16 Exchange servers, which can be geographically distributed to improve availability and resilience. The group of servers that replicate an Exchange database is called a Database Availability Group (DAG).
Exchange 2010 DAGs can also improve the reliability and performance of backup applications. Backing up a replicated, inactive copy of the database prevents the active Master database from being affected during the VSS snapshot.
Because all the servers in a DAG have copies of the database log files, applications can restore and recover databases by using backup components taken from different servers. When restoring a DAG database from backups, all active and passive copies must be restored using the same data.
For more information about how Database Mobility and Database Availability Groups affect Exchange 2010, see High Availability and Site Resilience.
For more information about how the backup and restore applications can use new DAG features, see Windows Server VSS Architecture.
Storage Configuration in Active Directory Changed
The arrangement of organization-level Exchange server and storage configuration information, which is stored in AD DS, has changed.
In versions of Exchange earlier than Exchange 2010, database and storage group configuration data is stored as children of the server object.
Because Exchange 2010 databases are no longer tied to a particular server, database configuration information is stored at the same hierarchy level as the Exchange server configuration objects. Similarly, DAG configuration is stored at the same level as the organization’s Exchange server configuration objects. Both forward links and back links exist between the database copies, the DAG they are a part of, and servers that participate in the DAG.
For more information, see Determining Exchange Server 2010 Storage Configuration.
Storage Configuration Commands Changed
To accommodate the many storage architecture changes in Exchange 2010, the Windows PowerShell commands for setting and retrieving storage configuration have changed significantly. For information about these changes, see Determining Exchange Server 2010 Storage Configuration.
CHKSGFILES DLL Now 64-bit Only
Exchange 2010 is only available in 64-bit implementation. 32-bit implementations of the server are not available. Similarly, the CHKSGFILES DLL is available only as a 64-bit unmanaged DLL. For more information, see System Requirements.
Single Copy Clustering Is Not Available
Exchange 2010 does not include support for Single Copy Clustering (SCC). If your Exchange 2007–compatible backup and restore application relies on SCC, you will need to modify the application to be compatible with Exchange 2010.
Log File Size Standardized
Exchange database log files are now each 1 MB in size. In earlier versions of Exchange, log files varied in size.