BBM Operation
BBM OperationThis 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 CacheMaximum 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 CapacityThe 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 |