The Intel® RAID Smart Battery AXXRSBBU4 supports RAID controllers that use a standard 256 MB or 512 MB DDR2 DIMM (Dual In-Line Memory Module). It is available as an accessory for selected RAID controllers and to support the ROMB (RAID-on-Motherboard) solutions used on the following Intel® products:-Intel® Server RAID Controller SRCSASRB.-Intel® Server RAID Controller SRCSATAWB.-Intel® Server System S7000FC4UR with a SAS riser card.
The Intel® Smart Battery AXXRSBBU4 contains the following components:-Board-to-board connector: The AXXRSBBU4 can connect to the base controller through the connector as a daughter card to the base controller.-Smart Battery circuit board: Ensures that the battery is maintained at optimal performance and charge levels. This circuit is based on the Texas Instruments bq2060A SBS v1.1-compliant gas gauge IC.-Battery pack: The battery pack is mounted to the circuit board. It includes a separate, internal circuit logic board and LiON (Lithium Ion) batteries. The logic board provides sensing and management logic to support battery charge, discharge, and monitoring.-Cable: A small cable connects the battery to the Smart Battery circuit board.-Monitoring / notification software: Monitoring is accomplished through the Intel® RAID BIOS Console 2, Intel® RAID Web Console 2, or Intel® RAID Command Line Utility 2 utilities. Software notifies the user of failures or corrective actions.
The battery pack charges automatically and communicates battery status information, such as voltage, temperature, and current to the host computer system.
Because it is faster to write data to the RAID adapter’s cache memory than it is to write it directly to a storage device, data is first written to the cache memory. These write operations are completed quickly at the software application level. The RAID controller then writes the cached data to the storage device when system activity is low or when the cache is full.
This method of writing data carries a risk. Cached data on the RAID controller can be lost if the AC power fails before the data is written to the storage device. The Intel® RAID Smart Battery AXXRSBBU4 mitigates this risk by providing battery power to the RAID controller if AC power is lost.
The Intel® RAID Smart Battery AXXRSBBU4 monitors the voltage level of the DRAM modules on the RAID controller. If the voltage drops below a predefined level, the Smart Battery switches the memory power source from the RAID controller to the battery pack. The battery pack provides power for the memory until the voltage returns to an acceptable level, at which time the Smart Battery circuit board switches the power source back to the RAID controller. Cached data is then written to the storage devices with no loss of data. The Smart Battery provides additionalfault tolerance when used with a UPS.
The battery pack cache-memory hold time depends on the size and configuration of the RAID controller memory. Retention time depends on memory capacity and the number of memory components on the DIMM to support the capacity. An estimated battery backup retention time is72 hours (three days).