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Appendix C: RAID Basics

Overview

A Redundant Array of Independent Disks (RA
that provide data security and high performance. A RAI
ID) is an array of several hard disks
D system accesses several
s simultaneously, which improves I/O performance over a single hard

Improved Performance

ovides access to several hard disk drives simultaneously, which greatly
e loss of data due to hard disk failure. A RAID offers additional
ard disk drives that can avert data loss from a hard disk drive failure. If a hard
n its other hard disk drives.
a
irements for performance
the system
The following is a description RAID level:

RAID 0

0 is best suited for app s that need h but do not require
high level of data security. The RAID 0 level provides the best performance of
ll the RAID levels, but it does not provide data redundancy.
RAID 0 uses disk striping and breaking up data into blocks to write across all hard
drives in the volume. The system can then use multiple hard drives for faster
read and write. The stripe size parameter that was set when the RAID was
created determines the size of each block. No parity calculations complicate the
write operation.
hard disk
disk. Data security is enhanced by a RAID, since data loss due to a hard disk
failure is minimized by regenerating redundant data from the other RAID hard
disks.

enefits B

RAID improves I/O performance, and increases data security through fault
tolerance and redundant data storage.
RAID pr
increases I/O performance.

Data Security

Hard disk drive failure unfortunately is a common occurrence. A RAID helps
prevent against th
h
drive fails, the RAID volume can regenerate data from the data and parity stored
o

RAID Levels

The Thecus N3200PRO supports standard RAID levels 0, 1, 5, and JBOD. You
choose a RAID level when you create a system volume. The factors for selecting
RAID level are:
Your requ
Your need for data security
Number of hard disk drives in the system, capacity of hard disk drives in
of each
RAID
alication igh bandwidth
a