BBM Operation

BBM Operation

This BBM consists of a Lithium-Ion battery, a charging circuit, and power monitoring circuitry. The controller is shipped with an optional BBM installed or with standard DIMM memory (without a BBM).

Set-up – Enabling the Write-Back Cache

Maximum RAID performance is achieved when the cache is in write-back mode. The write-back cache is enabled by toggling the write-back/write- through mode switch. The write-back/write-through mode switch is accessed using RAID EzAssist (the BIOS Configuration Utility) or in GAM. Refer to the RAID EzAssist Configuration Utility User Reference Guide or the Global Array Manager Client Software Installation Guide and User Manual for instructions on how to examine and change the mode switch.

Battery Backup Capacity

The battery backup’s capacity varies with the cache memory capacity used. In the event of a power failure, the battery backup can be expected to maintain cache data integrity for the periods of time shown in Table A-1.For more information about battery duration, please see “Battery Charge Life (Data Retention)” later in this chapter.

Table A-1. Typical Battery Backup Capacity

Memory Size

Approximate Battery Charge Life

 

 

32MB

168 hours

 

 

64MB

110 hours

 

 

128MB

60 hours

 

 

A-2

AcceleRAID 352 Installation Guide