LSI SAS2 manual Benefits and Features

Chapter 1: Introduction to the Integrated RAID Solution Benefits and Features SAS2 Integrated RAID Solution User Guide

1.2 Benefits and Features	The LSI Integrated RAID solution has the following benefits and features:
	 Support for up to 10 disks per Integrated RAID volume, with one or two volumes on
	each SAS2 controller. Each controller can support can support 14 volume drives,
	including one or two hot spare disks.
	 Support for two-disk Integrated Mirroring volumes (RAID 1)
	 Support for online capacity expansion (OCE) for RAID 1 volumes. OCE allows you to
	increase the size of a RAID 1 volume by replacing the disk drives with
	higher-capacity drives.
	 Low-cost RAID volume creation, which meets the needs of most internal RAID
	installations
	 Easy installation and configuration
	 Support for booting from any kind of Integrated RAID volume
	 Ability to operate without special operating system-specific software
	 High reliability and data integrity
	— Nonvolatile write journaling

1.2.1Host Interface

1.2.2Metadata Support

1.2.3 SMART Support

1.2.4 Fusion-MPT Support

—Physical disks in a volume are not visible to the operating system (OS) or to application software

Low host CPU and PCI bus utilization

Processing power provided by Fusion-MPT architecture

—Shared-memory architecture minimizes external memory requests

—Device hardware and firmware contain the functionality

The Integrated RAID host interface uses the message-passing interface, as described in the Fusion-MPT Message Passing Interface Specification. The Fusion-MPT interface gives the host OS access to the RAID volumes as well as to additional non-RAID physical disks.

The Integrated RAID firmware supports metadata, which describes the logical drive configuration stored on each member disk of a volume. After initialization, the firmware queries each member disk to read the metadata and verify the configuration. The firmware reduces the usable disk space for each member disk when it creates the the volume, which makes room for the metadata.

The Self-Monitoring Analysis and Reporting Technology (SMART) monitors disk drives for signs of future disk failure and generates an alert if it detects such signs. The Integrated RAID firmware polls each physical disk in the volume at regular intervals. If the firmware detects a SMART ASC/ASCQ code on a physical disk in the volume, it processes the SMART data and stores it in a log. The volume does not support SMART directly because it is only a logical representation of the physical disks in the volume.

The Integrated RAID BIOS uses the LSI Fusion-MPT interface to communicate to the SAS2 controller and firmware. This process includes reading the Fusion-MPT configuration to access the parameters that define behavior between the SAS2 controller and the devices that connect to it. The Fusion-MPT drivers for all supported operating systems implement the Fusion-MPT interface to communicate with the controller and firmware.

Page 6 LSI Corporation Confidential August 2010