ORA-00338 [11.2.0.1 Enterprise / MS Win Srv 2008 R2, Data Guard Broker (physical standby ASYNC), Fai

On a routine check of the alert log I discovered error ORA-00338. The database did not crash and is still online 24hrs later without any problems, including a 'clear' v$recover_file, and an RMAN backup.

During the error there were several log switches suddenly in quick succession during which point the standby Db lost contact and recovered from archive. There is however no clear indication whether the 'corrupt' logs are primary or standby.

The question is do I treat this as a cast-iron corruption and take proactive steps on the primary to validating the integrity of the database or is this a bug or temporary disk subsystem fault? I'm surprised are there no subsequent errors? This is a mission critical production environment and cannot be restarted unless in an emergency.