3.9 Managing Disk Controller Batteries

This section applies only to Exadata X4 and earlier systems, which use batteries to protect the disk controller cache. Newer disk controllers use a supercapacitor that does not require maintenance or replacement.

• About Disk Controller Batteries
  The disk controllers in Exadata X4 and earlier systems have a battery-backed write cache to accelerate write performance.
• Monitoring Storage Server Hard Disk Controller Batteries and Caching Mode
  The hard disk controller in Exadata X4 and earlier systems periodically performs a discharge and charge of the controller battery. During the operation, the write cache policy changes from write-back caching to write-through caching.
• Monitoring Batteries in the Database Servers
  
• Replacing Batteries in Disk Controllers