3Ware 9690SA-4I4E-SGL Installation Guide - Page 21

Chapter 3. Installing a Battery Backup Unit The Battery Backup Unit (BBU) is an optional add-on consisting of a control module and a battery pack. When used with the 3ware 9690SA RAID controller, the BBU control module is mounted on the RAID controller and the battery pack is installed on a remote battery board. The BBU's purpose is to supply power to the controller's memory module in the event of a system power loss. This allows the controller to safely use write-caching for optimal performance without exposing data to potential loss in the event of a system power failure. When fully charged, the battery preserves the contents of the controller cache memory for a limited period of time (up to 72 hours). When power is restored, cached data is written to disks. Items in Remote Battery Installation Package „ Battery Backup Unit (BBU) control module „ Battery „ Battery extension cable „ Remote battery board with full height bracket „ Low-profile bracket for low-profile enclosures. „ Remote Battery Installation Guide (This chapter covers same material) www.3ware.com 17