Appendix C: RAID Basics
Overview
A Redundant Array of Independent Disks (RA
that provide data security and high performance. A RAI
hard disk
s simultaneously, which improves I/O performance over a single hard
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.
B
enefits
RAID improves I/O performance, and increases data security through fault
tolerance and redundant data storage.
Improved Performance
RAID pr
ovides access to several hard disk drives simultaneously, which greatly
increases I/O performance.
Data Security
Hard disk drive failure unfortunately is a common occurrence. A RAID helps
prevent against th
e loss of data due to hard disk failure. A RAID offers additional
h
ard disk drives that can avert data loss from a hard disk drive failure. If a hard
drive fails, the RAID volume can regenerate data from the data and parity stored
o
n its other hard disk drives.
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
irements for performance
•
Your need for data security
•
Number of hard disk drives in the system, capacity of hard disk drives in
the system
The following is a description
RAID 0
RAID
0 is best suited for app
a
high level of data security. The RAID 0 level provides the best performance of
a
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.
ID) is an array of several hard disks
of each
RAID level:
lication
s that need h
94
D system accesses several
igh bandwidth
but do not require
a