LSI 25083 manual Peripheral devices, RAID levels

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.

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