Some of the new features of Exchange Server 2010 are that of the inclusion of two Volume Shadow Copy Service (VSS) Writers: the Replication Writer and the Store Writer. These writers make it easier for backup applications to create Windows Server 2008 VSS snapshots. For databases, Exchange Server includes the Replication Writer for replicating databases using the Database Mobility Features. And for those databases that are not replicated using a Database Availability Group (DAG) there is the Store Writer.

The Replication Writer is built into the Replication Service and is available on the passive node of the DAG server. The Replication Writer is used to support backing up particular databases that have had a shadow copy taken of the replicated instance of the transaction log files and of the replicated instance. By using the Store Writer, backups taken by Replication Writer can be restored to the active database location.

The Store Writer is built into the Exchange store and is available on any mailbox server. Store Writer is used for backing up and restoring active databases.

Sometimes, though, errors can occur during backups of the database. Such an example can happen if Windows Backup is used for a full backup. Exchange Server can produce an error such as this one:

“The application will not be available for recovery
from this backup. The consistency check failed for
 the component Microsoft Exchange Server
Microsoft Information StoreEXCHANGE{guid}.
Contact the application vendor for help.”

An administrator should always check the event log. Upon doing so they can expect to see a message such as the following:

“A VSS writer has rejected an event with error 0x800423f3,
The writer experienced a transient error. If the backup
process is retried, the error may not reoccur.”

“Changes that the writer made to the writer components
while handling the event will not be available to the
requester. Check the event log for related events from
the application hosting the VSS writer.”

Operation:
BackupComplete Event

Context:
Execution Context: Writer
Writer Class Id: {76fe1ac4-15f7-4bcd-987e-8e1acb462fb7}
Writer Name: Microsoft Exchange Replica Writer
Writer Instance Name: Exchange Replication Service
Writer Instance ID: {a53aea54-f2e5-4817-b03a-2743a05f3fda}
Command Line: “C:Program FilesMicrosoftExchange
ServerV14binmsexchangerepl.exe”
Process ID: 2968

One possible solution to the above error condition is to disable Microsoft Forefront Server Protections.

Another condition under which a system state backup can fail is if an incremental backup is attempted. If the server is running Forefront Protection for Exchange then it is possible for the backup to fail.while attempting to perform anything other than a full backup on a server running Forefront Protection for Exchange.

An administrator can determine if the failure is related to the Forefront Protection for Exchange by reviewing the Application Log and searching for the following error message:

“Error FSCVSSWriter 11003
Microsoft Forefront Protection VSS Writer failed when preparing for backup. Writer instance: FSCVSSWriter Error code: 0×00000000
Warning VSS 8229
A VSS writer has rejected an event with error 0x800423f0, The shadow-copy set contains only a subset of the volumes needed to correctly backup the selected components of the writer.

Changes that the writer made to the writer components while handling the event will not be available to the requester. Check the event log for related events from the application hosting the VSS writer.”

A supported hotfix is available from Microsoft that applies to Microsoft Forefront Protection 2010 for Exchange Server. However, this hotfix is intended to correct only the problem that has been described here. This hotfix should only be applied to systems that have experienced this specific problem. More information can be found about this hotfix by going to the Microsoft support site and reviewing article 2181692.

Other administrators have reported errors with the replicator service when they running in an Exchange Server cluster of two nodes.

When they launch TDP for mail, TDPEXC (TDPEXCC BACKUP * FULL /BACKUPMETHOD=VSS /BACKUPDESTINATION=TSM /Formreplica) on the passive node, they have reported the following error:

ANS5261W An attempt to create a snapshot has failed.
Another attempt will be made to create the snapshot in 30 seconds.
ANS1235E (RC-1) An unknown system error has occurred from which TSM cannot recover.
ACN5060E A Tivoli Storage Manager API error has occurred.

In this particular situation the backup action needs to backup the replication from the passive node. An administrator can run the following command from the exchange management shell:  “vssadmin list writers”.

The administrator should search for the line “Microsoft Exchange Writer” and check for an error message. If and error message is there then the administrator can restart the service “MSExchangeRepl” and try their backup again.