User`s guide

EK–SWRA2–IG. C01 1–1

Overview of RAID and RAID Array 200

Subsystems

This chapter presents definitions and descriptions of RAID (Redundant Array of

Independent Disks) subsystems, including the levels of RAID available to users of

StorageWorks RAID Array 200 Subsystems.

1.1 What is RAID?

Hardware RAID (Redundant Array of Independent Disks) is a set of multiple

disk drives and a specialized array controller that manages how data is

distributed across the disk drives.

Data for a given file is divided into segments (a group of blocks), which can be

written across multiple drives. By utilizing more than one drive, RAID arrays

provide three main benefits:

• Improved data availability through redundant configurations (RAID levels

1, 0 + 1, and 5)

• Improved I/O performance, higher data transfer rates compared to a single

drive

• Increased scaleability