This is an Exadata wait event that occurs when doing incremental level 1 backups via RMAN. Exadata automatically offloads RMAN backup activities to the storage cells. Solutions Offloading the RMAN backup activity to the storage cells within an Exadata machine is probably a good thing, so there may no tuning required. If RMAN backups are affecting performance, scheduling them at different times may be appropriate.
本文转自maclean_007 51CTO博客，原文链接:http://blog.51cto.com/maclean/1277894
