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BP1013 Best Practices for Enhancing Microsoft Exchange Server 2010 Data Protection and Availability 9
For additional information about DAG refer to Microsoft documentation:
Understanding Database Availability Groups , available at:
http://technet.microsoft.com/en-us/library/dd979799.aspx
2.2 Exchange 2010 database protection options
Microsoft Exchange 2010 offers a native subset of features that help in protecting the data present in
the mailbox databases and that can be coupled with traditional backup/recovery activities in order to
provide a higher data protection: DAG (multiple copy of a mailbox database), recoverable items (multi-
stages mailbox data deletion process), DAG lagged copy (point-in-time copy of the mailbox database).
Unlike its predecessors, Exchange 2010 offers support to back up its mailbox databases only through
the Volume Shadow Copy Service (VSS). VSS is a framework and a mechanism that allows consistent
copies of application datasets to be saved even when they are in use (mounted, open, or locked). To
achieve this result, VSS coordinates its actions with the line-of-business/corporate application (i.e.
Microsoft Exchange Server), the backup applications, and the storage container (system or hardware).
In this framework there are three main roles identified: the writers (applications such as Exchange
Server), the requester (protection applications such as ASM/ME or backup applications such as
Symantec™ Backup Exec™, CommVault Simpana
®
), and the providers (system provider or hardware
provider, such as EqualLogic).
For additional information about Volume Shadow Copy Service (VSS) refer to Microsoft
documentation:
Volume Shadow Copy Service , available at:
http://technet.microsoft.com/en-us/library/ee923636%28WS.10%29.aspx
Any Exchange-aware backup application that is able to interface the Exchange VSS writer will also be
able to take consistent backups of a mailbox database. To verify the required VSS writer is referenced
in the system, the following command can be issued in the CLI provided by the DISKSHADOW.EXE
system tool:
DISKSHADOW>list writer status
When the Exchange writer is present, the output should include an element similar to the one in the
red box.
When an Exchange DAG is used, the backup of the passive copy or copies flow through the Microsoft
Exchange Replication Service VSS writer while the backup of the active copy of the databases still
happens through the regular VSS writer as shown above.