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4chapter 2 raid technology overview – HP EliteBook 2170p Notebook PC User Manual

Page 8

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RAID levels

Function/Applications

Advantages/Disadvantages

RAID 1

Function:

Identical (mirrored) data is
stored on two drives.

Applications:

Accounting

Payroll

Financial

Advantages:

Provides high fault
tolerance.

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 (see

HP SATA drive option kits
on page 6

).

RAID Recovery

Function:

Identical (mirrored) data is
stored on two drives.

Boosts the functionality of
RAID 1 with valuable
features.

Applications:

Any application that requires
a simple data protection
method.

Advantages:

Provides high fault
tolerance.

Users can choose to mirror
data continuously or on
request.

Data recovery is quick and
easy.

Allows hot-plugging of
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