RAID levels

Function/Applications

Advantages/Disadvantages

 

 

 

RAID 1

Function:

Advantages:

 

Identical (mirrored) data is

Provides high fault

 

stored on two drives.

tolerance.

 

Applications:

Disadvantages:

 

●

Accounting

Only half of the total drive

 

●

Payroll

capacity can be used for

 

storage.

 

 

 

 

●

Financial

Storage space may be

 

 

 

 

 

 

wasted if the capacities of

 

 

 

the primary and recovery

 

 

 

hard drives are different (see

 

 

 

HP SATA drive option kits

 

 

 

on page 6).

 

 

 

RAID Recovery

Function:

Advantages:

 

Identical (mirrored) data is

Provides high fault

 

stored on two drives.

tolerance.

 

Boosts the functionality of

Users can choose to mirror

 

RAID 1 with valuable

data continuously or on

 

features.

request.

 

Applications:

Data recovery is quick and

 

Any application that requires

easy.

 

Allows hot-plugging of

 

a simple data protection

 

method.

mirrored drive (with eSATA

 

 

 

or docking station hard

 

 

 

drive).

Enables easy migration to non-RAID.

Disadvantages:

Only half of the total drive capacity can be used for storage.

Storage space may be wasted if the capacities of the primary and recovery hard drives are different.

RAID 5

Function:

 

Distributes data across three

 

hard drives. If one hard drive

 

fails, RAID 5 allows data to

 

be recovered from the other

 

two hard drives.

 

Applications:

 

A good choice for large

 

amounts of critical data.

Advantages:

Data redundancy

Improved performance and capacity

High fault-tolerance and read performance

Disadvantages:

During a RAID rebuild after a hard drive fails, system performance can be decreased.

4 Chapter 2 RAID technology overview