Adaptec 2120S, 2200S manual Simple Volume, Spanned Volume

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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