Chapter 1. Introduction to the 3ware Command Line Interface

Array Roaming. The process of removing a unit from a controller and putting it back later, either on the same controller, or a different one, and having it recognized as a unit. The disks may be attached to different ports than they were originally attached to, without harm to the data.

For definitions of other terms used throughout the documentation, see the “Glossary”.

Available RAID Configurations

RAID is a method of combining several hard drives into one unit. It offers fault tolerance and higher throughput levels than a single hard drive or group of independent hard drives. RAID levels 0, 1, 10 and 5 are the most popular. AMCC's 3ware controllers support RAID 0, 1, 5, 6, 10, 50, JBOD and Single Disk. The information below provides a more in-depth explanation of the different RAID levels.

For how to configure RAID units, see “Configuring a New Unit” on page 96.

RAID 0

RAID 0 provides improved performance, but no fault tolerance. Since the data is striped across more than one disk, RAID 0 disk arrays achieve high transfer rates because they can read and write data on more than one drive simultaneously. The stripe size is configurable during unit creation. RAID 0 requires a minimum of two drives.

When drives are configured in a striped disk array (see Figure ?), large files are distributed across the multiple disks using RAID 0 techniques.

Striped disk arrays give exceptional performance, particularly for data intensive applications such as video editing, computer-aided design and geographical information systems.

RAID 0 arrays are not fault tolerant. The loss of any drive results in the loss of all the data in that array, and can even cause a system hang, depending on your operating system. RAID 0 arrays are not recommended for high availability systems unless additional precautions are taken to prevent system hangs and data loss.

Figure 1. RAID 0 Configuration Example

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3ware Serial ATA RAID Controller CLI Guide

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AMCC 9550SX, 9500S, 9590SE, 9650SE manual Available RAID Configurations, Raid