Chapter 10. Maintaining Your Controller186 3ware Serial ATA RAID Controller User GuideViewing Battery InformationThe Battery Backup Unit (BBU) is an add-on card that can be attached to a3ware 9000 RAID controller to supply power from a battery pack in the eventof a system power loss. This allows the controller to use write-caching foroptimal performance and to preserve data in the event of a system powerfailure. When fully charged, the battery preserves the contents of the cachememory for up to 72 hours. When power is restored, the cached write data iswritten to the disks.You can see information about a battery backup unit attached to yourcontroller in both 3DM 2 and 3BM.To view information about a BBU in 3DM 2• On the menu bar, choose Monitor > Battery Backup.The Battery Backup page appears, on which you can see details and statusabout the unit. This page is refreshed every 30 seconds.For details about the fields on this page, see “Battery Backup page” onpage 213.To view information about a BBU in 3BM• At the main 3BM screen, tab to the Information button and press Enter.On the pop-up menu, select Battery Backup and press Enter.The Battery Backup Unit screen appears.The fields on this screen are the same as those available through 3DM.For details about the fields, see “Battery Backup page” on page 213.Note: When the BBU status is not “Ready,” write caching is automatically disabledon all units attached to the controller
