HP A7143A RAID160 SA Controller Support Guide, February 2007

RAID Technology Overview

Smart Array Controller Supported RAID Configurations

Chapter 1

Smart Array Controller Supported RAID Configurations

RAID 0—No Fault Tolerance

The RAID 0 configuration enhances performance with data striping, but there is no data redundancy to

protect against data loss when a physical disk fails. RAID 0 is useful for rapid storage of large amounts of

non-critical data (for printing or image editing, for example), or when cost is the most important consideration

(see Figure 1-4 on page 16).

Figure 1-4 Data Striping (S1-S4) of Data Blocks B1-B12

The advantages of RAID 0 are as follows:

• Highest performance configuration for writes

• Lowest cost per unit of data stored

• All disk capacity is used to store data (none needed for fault tolerance)

The disadvantages of RAID 0 are as follows:

• All data on the logical drive is lost if a physical disk fails.

• Online spare disks are not available.

• Data preservation by backing up to external disk drives only.

RAID 1—Disk Drive Mirroring

In this configuration, only two physical disks are present in the array. Data is duplicated from one disk onto

the other disk creating a mirrored pair of disk drives, but there is no striping of data (see Figure 1-5, “Disk

Drive Mirroring of P1 onto P2 (RAID 1),”).

B11B10 B12