Figure 2.1 Disk Striping

MegaRAID Controller

Segment 1

Segment 2

Segment 3

Segment 4

Segment 5

Segment 6

Segment 7

Segment 8

Segment 9

Segment 10

Segment 11

Segment 12

Disk striping involves partitioning each disk drive’s storage space into stripes that can vary in size from 2 to 128 Kbytes. These stripes are interleaved in a repeated, sequential manner. The combined storage space is composed of stripes from each drive. MegaRAID SCSI 320-0 supports stripe sizes of 2, 4, 8, 16, 32, 64, or 128 Kbytes.

For example, in a four-disk system using only disk striping (as in RAID level 0), segment 1 is written to disk 1, segment 2 is written to disk 2, and so on. Disk striping enhances performance because multiple drives are accessed simultaneously; but disk striping does not provide data redundancy.

2.3.5.1Stripe Width

Stripe width is a measure of the number of disks involved in an array where striping is implemented. For example, a four-disk array with disk striping has a stripe width of four.

RAID Overview

2-5

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