SAS2 Integrated RAID Solution User Guide
Chapter 2: Overview of Integrated RAID Mirrored Volumes
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Introduction
LSI Corporation Confidential
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August 2010
Page 7
Chapter 2
2.1 Introduction
As a result of the shift towards network-attached storage (NAS), Internet service
providers need a cost-effective, fault-tolerant solution to protect the operating systems
on small form-factor, high-density, rack-mountable servers. The mirroring features of
the LSI Integrated RAID solution provide data protection for the system boot volume,
which safeguards the operating system and other critical information on servers and
high-performance workstations. The Integrated RAID solution supports the following
types of mirrored arrays:
The Integrated Mirroring solution, which provides features of RAID 1
The Integrated Mir Striping solution, which provides features of RAID 10
The Integrated Mirroring Enhanced
solution, which provides features of RAID 1
Enhanced (RAID 1E)
These three mirroring solutions provide a robust, high-performance, fault-tolerant
solution to data storage needs at a lower cost than a dedicated RAID controller.
Mirrored volumes may have from two-to-ten disks to provide fault-tolerant protection
for critical data. Mirrored volumes also support one or two global hot spare drives, with
a maximum of 14 drives on each LSI SAS2 controller.
NOTE:
Fourteen drives is the
theoretical
upper limit for a single LSI SAS2 controller,
although the controller itself may support fewer than 14 drives. You can also configure
one mirrored volume and one Integrated Striping volume on the same LSI SAS
controller.
Each SAS2 controller can have two global hot spare disks available to automatically
replace a failed disk in the one or two mirrored volumes configured on the controller.
The hot spares make the mirrored volumes even more fault-tolerant.
2.2 Integrated Mirroring and
Integrated Mirroring Enhanced
Features
Integrated Mirroring, Integrated Mir Striping, and Integrated Mirroring
Enhanced volumes support the following features:
Configurations of one or two mirrored volumes on each LSI SAS2 controller. Each
volume can consist of two mirrored disks for an Integrated Mirroring volume;
three-to-ten mirrored disks for an Integrated Mirroring Enhanced volume; or four,
six, eight, or ten mirrored disks for an Integrated Mir Striping volume.
(Optional) Two global hot spare disks per LSI SAS2 controller to automatically
replace failed disks in mirrored volumes.
Overview of Integrated RAID Mirrored Volumes
This chapter provides an overview of the LSI Integrated RAID features that support the
creation of mirrored arrays.
