Avago Technologies Cache Protection for RAID Controller Cards - Manual (Page 5)

LSI Corporation
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12Gb/s MegaRAID SAS RAID Controllers User Guide
April 2014
Chapter 1: Overview
Overview
Chapter 1: Overview
This document is the primary reference and user’s guide for the LSI® MegaRAID® SATA+SAS RAID controllers based on
the 12Gb/s SAS/SATA RAID-on-a-chip (ROC) devices. This document contains complete installation instructions and
specifications for these RAID controllers.
1.1 Overview
The 12Gb/s MegaRAID SATA+SAS RAID controllers are high-performance intelligent PCIe®-to-SATA+SAS controllers
with RAID control capability. The 12Gb/s MegaRAID SATA+SAS RAID controllers provide reliability, high-performance,
and fault-tolerant drive subsystem management. They are an ideal RAID solution for the internal storage of
workgroup, departmental, and enterprise systems. The 12Gb/s MegaRAID SATA+SAS RAID controllers offer a
cost-effective way to implement RAID in a server.
SAS technology brings a wealth of options and flexibility with the use of SAS devices and SATA devices within the
same storage infrastructure. However, SAS devices and SATA devices bring individual characteristics that make each
one a more suitable choice depending on your storage needs. MegaRAID technology gives you the flexibility to
combine these two similar technologies on the same controller, within the same enclosure, and in the same
virtual drive.
NOTE Carefully assess any decision to mix SAS drives and SATA drives within
the same virtual drive. Although you can mix drives, the practice is
strongly discouraged.
LSI offers a family of MegaRAID SATA+SAS RAID controllers that address the needs for both internal and external
solutions. The 12Gb/s MegaRAID SATA+SAS RAID controllers are based on the LSI first-to-market SAS technology and
proven MegaRAID technology. As third-generation PCIe RAID controllers, these controllers address the growing
demand for increased data throughput and scalability requirements across midrange and enterprise-class server
platforms. These controllers provide these features:
 12Gb/s Serial Attached SCSI (SAS) performance
 6Gb/s SATA III performance
 Eight-lane, 8 GT/s PCIe host interface
1.1.1 SAS/SATA Standards and Communication Protocols
MegaRAID SATA+SAS controllers support the ANSI® Serial Attached SCSI standard, version 3.0. In addition, the controller
supports the SATA III protocol defined by the Serial ATA specification, version 3.0. Supporting both the SAS interface
and the SATA interface, the SAS controller is a versatile controller that provides the backbone of both server and
high-end workstation environments.
Each port on your MegaRAID SAS RAID controller supports SAS devices, SATA devices, or both, by using the
following protocols:
 SAS Serial SCSI Protocol (SSP), which enables communication with other SAS devices
 SATA, which enables communication with other SATA devices
 Serial Management Protocol (SMP), which communicates topology management information directly with an
attached SAS expander device
 Serial Tunneling Protocol (STP), which enables communication with SATA devices through an attached expander