Exchange 2003 VSS Backup Solution
For IBM Storage DS8000/DS6000
And Symantec Backup Exec 11d
Page 5 David West, David Hartman
©Copyright IBM Corp. 2007
Customers rely on Microsoft Exchange, SQL Server, and various
internet/intranet applications as key business applications. Even short periods
of unexpected downtime can have a serious impact. The capability of backing
up and restoring data quickly and consistently is essential. The problems in
backing up large amounts of data, such as backup jobs frequently
overflowing their backup window, and having open file and application issues,
led to the development of snapshots.
The capability to take snapshots has been around for several years.
Snapshots allow administrators to “snap” a copy of data while allowing
applications to continue running. Applications are paused just long enough to
allow the disk system to create the snap copy. These volumes could then be
mounted to another server for backing up to various storage devices.
Snapshots, however, depended on tight hardware and software compatibility
which was often problematic, inducing errors that were difficult to track and
resolve. In addition, the vendors needed to support various versions of SQL
Server, Microsoft® Exchange, Windows® Server, and myriad other
applications.
Microsoft developed VSS (Volume Shadow Copy Service) as a common
framework to resolve these issues. Available in Windows Server 2003,
software and hardware vendors now have a common interface model for
generating snapshots. The VSS framework specifies how three distinct
components should interact. The three different components are the VSS
requestor, writer, and provider. The requestor is the backup software, such as
the Backup Exec Agent. The writer is the application software such as SQL
Server or Exchange Server that pause to allow the snapshots to be taken.
The provider is the specific hardware/software combination that generates
the snapshot volume, in this case, the IBM System Storage™ DS Hardware
Provider.
The Importance of Exchange VSS Solutions Businesses have grown to rely on access to their Microsoft Exchange servers
to address the increasing demands of mobile computing, global business and
electronic commerce. They depend on Exchange e-mail, group scheduling,
and calendars for critical business communication and key business
processes. E-mail also supports vital applications needed for functions such
as workflow, collaboration, and knowledge management. According to
Microsoft, nearly 45 percent of business-critical information is housed in e-
mail and e-mail-attached documents.