Hardware User's Guide

Intel® RAID Controller RS25SB008 Hardware User’s Guide 25
SAS Expander Support
The Intel
®
RAID Controller RS25SB008 supports LSI* expanders, Vitesse SAS
expanders, and PMC expanders that are used as a component in Intel and 3rd party
enclosures. Other expanders may be supported post launch, based on market conditions
and customer requirements.
Support for Non-Hard Disk Drive Devices
Selected non-hard drive devices are supported for use with this controller. For information
on support for non-hard drive devices, see this RAID controller’s Tested Hardware and
Operating System List.
Enclosure Management Support
The Intel
®
RAID Controller RS25SB008 supports SES2 enclosure management in-band
to expander-based backplanes.
RAID Functionality and Features
Hierarchy
The fundamental purpose of a RAID system is to present a usable data storage medium
(virtual drive) with some level of redundancy to a host operating system. The Intel
®
RAID firmware is based on the concept of associating physical drives in arrays and then
creating a virtual drive from that array that includes a functional RAID level. To create a
virtual drive and present it to the host operating system, the RAID firmware typically
follows these steps:
1. One or more physical drives are selected and associated as an array.
2. One or more arrays are a
ssociated and given a RAID level. This process creates a
virtual drive and provides an option t
o initialize the virtual drive.
3. The RAID firmware presents the virtual drive to the operating system.
RAID Physical Drive Status
Table 11. RAID Physical Drive Status
Drive State Code Description
Unconfigured Good Unconfigured Good The drive is functioning normally, but is not part of a
configured virtual drive a
nd is not a hot spare.
Online ONLN The drive is online, is part of a configured 
virtual drive, and is functioning normally.