User`s guide

5.2.2 Integrated Mirroring Overview

This section provides an overview of the LSI Logic Integrated Mirroring (IM) feature.

5.2.2.1 Introduction

As a result of the shift towards Network Attached Storage (NAS), ISPs need a cost effective, fault-

tolerant solution to protect the operating systems on small form factor, high-density, rack-mountable

servers. The LSI Logic Integrated Mirroring (IM) feature—which includes Integrated Mirroring Enhanced

(IME)— provide data protection for the system boot volume to safeguard critical information such as the

operating system on servers and high performance workstations. The Integrated Mirroring feature gives

customers a robust, high-performance, fault-tolerant solution to their storage needs, at a lower cost than

a dedicated RAID controller.

The Integrated Mirroring feature supports simultaneous mirrored volumes with two disks (IM) or three to

eight disks (IME), to provide fault-tolerant protection for critical data. (If a hot spare disk is used, the

maximum volume size is seven mirrored disks, plus the hot spare disk.) Up to two IM volumes are

supported per SAS controller, with up to ten drives total per controller.

If a disk in an Integrated Mirroring volume fails, the hot swap capability allows the volume to be easily

restored by simply swapping disks. The firmware then automatically re-mirrors the swapped disk.

Additionally, each SAS controller can have one global hot spare disk available to automatically replace a

failed disk in the one or two IM or IME volumes configured on the controller. The hot spare makes the

Integrated Mirroring volume even more fault-tolerant.

Note

You can configure an Integrated Mirroring volume and an Integrated Striping volume on

the same LSI Logic SAS controller

The IM feature uses the same device drivers as the standard LSI Logic Fusion-MPT based controllers,

providing seamless and transparent fault tolerance. This eliminates the need for complex backup software

or expensive RAID hardware. The IM feature operates independently from the operating system, in order

to conserve system resources. The BIOS based configuration utility makes it easy to configure IM and

IME volumes.

The Integrated Mirroring feature is currently available as an optional component of the Fusion-MPT

architecture on LSI Logic controller products.