RAID - User Guide

RAID levels Function/Applications Advantages/Disadvantages
Applications:
●
Accounting
●
Payroll
●
Financial
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.
Fault tolerance
Fault tolerance is the ability of a RAID array to withstand and recover from a drive failure. Fault
tolerance is provided by redundancy. Therefore, RAID 0 has no fault tolerance because it does not
copy data to another hard drive. With RAID 1 and Recovery, one drive can fail without causing the
4 Chapter 2 RAID technology overview