The Certkiller administrator is in the process of configuring a new RAID array and wants to know which of the RAID levels uses disk mirroring, and/or disk duplexing, where duplicate information is stored on both drives?

A.
RAID 0

B.
RAID 5

C.
RAID 1

D.
RAID 3

Explanation:
The RAID 1 implementation uses disk mirroring, and/or disk duplexing, where duplicate information is stored on both drives.
Incorrect Answers:
A: RAID 0 is the simplest level, and uses disk striping without parity thus it requires less time for disk access, but no redundancy or error correction is provided making this type of RAID solution only to be used when reliability is not vital.
B: RAID 5 is used to distributes its parity blocks among its independent data disks.
D: The RAID 3 specification is designed to use parallel transfers similar to RAID 2, along with byte-level parity striping.
Reference:
Charles J. Brooks, Server+ Certification Exam Cram 2 (Exam SK0-002), QUE Publishing, Indianapolis, 2006, pp. 186