When performing a flat file backup of open Oracle database datafiles, the Oracle instance terminates.

Article:TECH5227  |  Created: 2009-01-23  |  Updated: 2011-12-07  |  Article URL http://www.symantec.com/docs/TECH5227
Article Type
Technical Solution


Issue



When performing a flat file backup of open Oracle database datafiles, the Oracle instance terminates.


Solution




This Issue occurs only if the following conditions are met:

1. The Oracle database is in an Open state.

2. The datafiles are backed up with the Symantec Backup Exec (tm) Backup Open Files option set to Yes, with a lock (Figure 1).

 
Figure 1
 
 
 

3. Changes are being made to the database while the datafiles are backed up.


NOTE:
This issue is not related to the Backup Exec for Windows Servers Oracle Agent. This problem will normally be seen when a backup operation is performed that consists of the Oracle database server's local drives (which contain the database datafiles). Because Oracle does not use exclusive locks for the datafiles by design, Oracle recommends that a flat file backup only be performed when the database is closed or in an offline state. To perform online backups of an Oracle database, the Backup Exec Oracle Agent must be used to ensure database integrity.

If changes are being made to the database when Backup Exec places a lock on the open datafile, Oracle will not be able to write to the file, and will terminate the instance. If the database is dormant or only read operations are taking place, the instance will not be affected.


According to the Oracle Press Backup and Recovery Handbook:


Normally, to resolve an instance failure, the instance would be shut down and restarted. Crash recovery or instance recovery is automatic. Depending on the amount of work that is being done at the time of the failure, database instance failures might take a long time to recover. For example, suppose a transaction has updated a huge table and decided to roll back, but before the transaction finished rolling back, the instance fails. Crash recovery has to do roll forward and then transaction recovery has to roll the transaction back, which might take a long period of time.


To avoid this problem, only run flat file backups of Oracle while the database is shutdown. Alternatively, be sure that the backup operation that contains the drive with the datafiles has the Backup Open Files option set to something other than Yes, with a lock.



Legacy ID



191592


Article URL http://www.symantec.com/docs/TECH5227


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