Figure2.1 disk striping, 1 stripe width – LSI MegaRAID SCSI 320-2 RAID Controller Series 518 User Manual

Page 29

Advertising
background image

RAID Overview

2-5

Copyright © 2002 by LSI Logic Corporation. All rights reserved.

Figure 2.1

Disk Striping

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 320-2
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.

2.3.5.1

Stripe 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.

Segment 1
Segment 5
Segment 9

Segment 2
Segment 6

Segment 10

Segment 3
Segment 7

Segment 11

Segment 4
Segment 8

Segment 12

MegaRAID Controller

Advertising