Glossary
103
Glossary
A
DAPTER
—An adapter enables the system to access peripheral devices by
converting the protocol of one bus or interface to another. An adapter may also
provide specialized function. For example, a RAID controller is a type of adapter that
provides RAID functions. Adapters may reside on the system board or be an add-in
card. Other examples of adapters include network and SCSI adapters.
AHCI — A programming specification which defines the operation of Serial ATA
host controllers (also known as host bus adapters) in a non-implementation-specific
manner. The specification describes a system memory structure for computer
hardware vendors to exchan ge data between host system memory and attached
storage-devices.
ATA (A
DVANCED
T
ECHNOLOGY
A
TTACHMENT
)—A standard interface for
connecting a system’s storage devices, such as CD-ROMs and hard-drives.
ATAPI (ATA P
ACKET
I
NTERFACE
)—An interface standard that defines the packet
protocol between a system and its internal storage peripherals, such as CD-ROM,
DVD, or tape drives. ATAPI provides the command set for controlling the devices via
an IDE interface.
B
ACKGROUND
I
NITIALIZATION
—Background initialization is the automatic check
for media errors on physical disks. It ensures that striped data segments are the same
on all physical disks in a virtual disk. The difference between a background
initialization and a consistency check is that a background initialization is automatic
for new virtual disks. The operation starts automatically after you create the disk.
BAS (B
ACKGROUND
A
RRAY
S
CAN
)—Background Array Scan is a background
operation which gets executed every 100msec. that verifies and corrects the mirror,
volume or parity data for virtual disks. BAS starts automatically after a Virtual Disk is
created.
BIOS (B
ASIC
I
NPUT
/O
UTPUT
S
YSTEM
) C
ONFIGURATION
U
TILITY
—An alternate
name for the PERC Virtual Disk Management utility. The utility appears during
system startup when <Ctrl><R> are pressed.
C
ACHE
—Fast memory that holds recently accessed data. Using cache speeds
subsequent access to the same data. It is most often applied to processor-memory
access but also can be used to store a copy of data accessible over a network. When
data is read from or written to main memory, a copy is also saved in cache memory
with the associated main memory address. The cache memory software monitors the
addresses of subsequent reads to see if the required data is already stored in cache
memory. If it is already in cache memory (a cache hit), it is read from cache memory
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