Adaptec SCSI RAID 2120S/2200S Software User’s Guide

RAID-50

A RAID-50 is a dual-level array created by using two or more equal-sized RAID-5s to create a RAID-0.

RAID-50

RAID-5

Data 0 & Data 1

Data 4 & Data 5

Data 8 & Data 9

Data 12 & Data 13

Top-Level Arrays

RAID-5

Data 2 & Data 3

Data 6 & Data 7

Data 10 & Data 11

Data 14 & Data 15

Drive

Drive

Drive

Drive

Drive

Drive

Data 0

Data 1

Parity A0

Data 2

Data 3

Parity B0

Data 4

Parity A1

Data 5

Data 6

Parity B1

Data 7

Parity A2

Data 8

Data 9

Parity B2

Data 10

Data 11

Data 12

Data 13

Parity A3

Data 14

Data 15

Parity B3

Second-Level Arrays

The top level RAID-0 shares the load among the second-level RAID-5s, improving both read and write performance. The second level RAID-5s use of parity provides efficient redundancy.

Simple Volume

A simple volume consists of a single disk drive.

Spanned Volume

A spanned volume is created by joining two or more disk drives. The drives do not have to be of equal capacity and are connected end-to-end. A spanned volume offers no redundancy and no performance advantage over a single drive.

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