LSI 25083 - page 75

A-3

peripheral

devices

A piece of hardware (such as a video monitor, drive, printer, or CD-ROM)

used with a computer and under the control of the computer. SCSI

peripherals are controlled through a SAS MegaRAID SAS RAID

controller (host adapter).

PHY The interface required to transmit and receive data packets transferred

across the serial bus.

Each PHY can form one side of the physical link in a connection with a

PHY on a different SATA device. The physical link contains four wires that

form two differential signal pairs. One differential pair transmits signals,

while the other differential pair receives signals. Both differential pairs

operate simultaneously and allow concurrent data transmission in both

the receive and the transmit directions.

RAID Acronym for Redundant Array of Independent Disks (originally

Redundant Array of Inexpensive Disks). An array of multiple independent

drives managed together to yield higher reliability, performance, or both

exceeding that of a single drive. The RAID array appears to the controller

as a single storage unit. I/O is expedited because several drives can be

accessed simultaneously. Redundant RAID levels (RAID levels 1, 5, 6,

10, 50, and 60) provide data protection.

RAID levels A set of techniques applied to drive groups to deliver higher data

availability, performance characteristics, or both to host environments.

Each virtual drive must have a RAID level assigned to it.

SAS Acronym for Serial Attached SCSI. A serial, point-to-point,

enterprise-level device interface that leverages the proven SCSI protocol

set. The SAS interface provides improved performance, simplified

cabling, smaller connections, lower pin count, and lower power

requirements when compared to parallel SCSI. SAS controllers leverage

a common electrical and physical connection interface that is compatible

with Serial ATA. The SAS controllers support the ANSI Serial Attached

SCSI Standard, Version 2.0. In addition, the controller supports the

Serial ATA II (SATA II) protocol defined by the Serial ATA Specification,

Version 1.0a. Supporting both the SAS interface and the SATA II

interface, the SAS controller is a versatile controller that provides the

backbone of both server and high-end workstation environments. Each

port on the SAS RAID controller supports SAS devices, SATA II devices,

or both.