Battery Backup Module; Bios; Cache; Consistency Check - Areca ARC-1110 User Manual

GLOSSARY

Battery Backup Module

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.

BIOS

(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.

Cache

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

Consistency Check

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.

Driver

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.
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