In Backup Exec 2012, some Exchange 2013 CU1 or CU2 backups may appear to succeed, but restore attempts fail.

Article:TECH212466  |  Created: 2013-11-13  |  Updated: 2014-02-26  |  Article URL http://www.symantec.com/docs/TECH212466
Article Type
Technical Solution

Product(s)

Issue



Backups of Microsoft Exchange 2013 may not be restorable with roll-forward of transaction logs due to invalid metadata accompanying the Exchange snapshot.  In Backup Exec 2012, this invalid metadata is not detected at backup time, which means that backups may appear to succeed but not be restorable.

The following restore operations fail:

  • Restoring a database from a FULL backup with the roll-forward option
     
  • Restoring a database from a FULL backup plus either a cumulative incremental backup or one or more differential backups - in this case, Backup Exec fails when it applies the incremental backups as roll-forward restores based on the restored FULL image

 

 

Future Backup Exec releases will avoid these potential data loss conditions by failing the backups after detecting the flaw in the snapshot.

 

 


Error



 

A restore failure from a Backup Exec 2012 backup produces the following entry in the Application Event Log:
Log Name: Application
Source:      MSExchangeRepl
Event ID:    4356
Description:
Exchange Replication Service VSS Writer failed restoring a backup for '<database name>' because an unexpected error (-2147023286) was encountered while attempting to locate existing log files in the log file directory '<database path>'.

 

 


Environment



This issue only affects Microsoft Exchange 2013 CU1 or CU2 (Cumulative Update 1 or Cumulative Update 2) backups taken under Backup Exec 2012.

 


Cause



When the snapshot is taken, the Microsoft Exchange VSS Writer produces a Backup Components Document that lacks the LOG_SIGNATURE_XXXX information needed to apply the transaction logs to the database at restore time.  This has been seen to occur after the Exchange server was restarted and on other occasions.

Symantec expects that a forthcoming Microsoft Knowledge Base article will be published containing more information on this Exchange issue and how to correct it.  A hyperlink will be attached to this article when it is available.

 

 


Solution



The formal resolution for this issue is included in the following releases:  Backup Exec 2012 Rev 1798 Service Pack 3 (TECH205351).

Refer to the Hotfix link under Related Documents at the end of this article to obtain the hotfix needed to resolve the issue.

 

In Backup Exec 2012 SP3, Backup jobs affected by this issue will fail with: An error occurred while accessing Microsoft Exchange Server. Check the application event log on the Exchange Server for more details.”
 
 
The detail in the Job log file will show:
The consistency check of the snapshot for the Microsoft Exchange database %s has failed. You should check for possible data corruption in the Exchange Server that is online.
 
 
The Backup Exec Remote Agent Debug log (Beremote) on the Exchange server will show the following:
The LOG_SIGNATURE_ID and LOG_SIGNATURE_TIMESTAMP in the Backup Components Document are both 0. This appears to be a known Exchange 2013 problem"
 
 
NOTE: This is a known Exchange 2013 problem.
 
Note that while the Symantec resolution corrects the reporting of the issue, it does not resolve the underlying Exchange issue. A fix for this issue is expected in a future update to Exchange.
 
 
 
Best Practices:
Symantec strongly recommends the following best practices
1. Always perform a full DR backup prior to making any changes to your environment.
2. Always make sure that your environment is running the latest version and patch level.
3. Perform periodic "test" restores.
4. Subscribe to technical articles.
 

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Supplemental Materials

SourceETrack
Value3237633
Description

Report an error if the BCD returned by the Exchange writer is invalid




Article URL http://www.symantec.com/docs/TECH212466


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