Areca ARC-1231ML/1261ML/1280ML User Manual

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Many modern RAID controllers are armed with a battery backup Mod-

ule (BBM). While an UPS protects most servers from power fluctua-

tions or failures, a BBM provides an additional level of protection. In 

the event of a power failure, a BBM supplies power to retain data in 

the RAID controller’s cache, thereby permitting any potentially dirty 

data in the cache to be flushed out to secondary storage when power 

is restored.

(Basic Input/Output System) software is stored on a chip and provides 

an interface between the operating system and the hardware. Usually 

the BIOS is built into a ROM chip installed on the motherboard so that 

the BIOS will always available and not affected by disk failure.

Controller memory used to speed up data transfer to and from a disk.

In RAID, check consistency verifies the correctness of redundant data 

in an array. For example, in a system with dedicated parity, checking 

consistency means computing the parity of the data drives and com-

paring the results to the contents of the dedicated parity drive.

It is a piece of software – that is often executed in kernel mode – that 

controls a hardware device. Typically drivers provide an interface by 

which applications can use the device in a uniform and hardware-inde-

pendent manner.

Hot Spare

An extra physical disk drive in a RAID configuration that controller can 

use to automatically rebuild a system drive when another drive fails. 

The hot spare drive must have at least as mush capacity as the largest 

disk drive in the array or the rebuild may not start.