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Comparing raid levels – StorCase Technology DS570 User Manual

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Appendix B - Array Basics

StorCase Technology, Inc.

DS560/DS570 User's Guide - Rev. A04

Table B-1: RAID Level Comparisons

Comparing RAID Levels

Table B-1 illustrates the differences between the various RAID levels.

RAID

Level

Minimum #

of Drives

Description

Pros

Cons

RAID 0

2

Data striping

without

redundancy

Highest

performance

No data protection - if

one drive fails, all data

is lost

RAID 1

2

Disk mirroring

Very high

performance and

data protection

Good write

performance

High redundancy

costs - twice the

storage capacity is

required

S_IDERAID

RAID 5

3

Block-level data

striping with

distributed parity

Best cost and

performance for

transaction-

oriented networks

Very high

performance and

data protection

Supports multiple

simultaneous

read/writes

Can also be

optimized for

large, sequential

requests

Write performance is

slower than RAID 0 or

RAID 1

RAID 10

RAID 0/1

3

Combination of

RAID 0 (data

striping) and

RAID 1

(mirroring)

Highest

performance and

data protection

(can tolerate

multiple drive

failures)

High redundancy costs -

twice the storage

is capacity required

RAID 3

3

Block-level data

striping with

dedicated parity

drive

Excellent

performance for

large, sequential

data requests

Poorly suited for

transaction-oriented

network applications

Single parity drives do

not support multiple,

simultaneous read/write

requests

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