The only difference between RAID 3 and RAID 4 is that level 3 is implemented at the byte level while level
4 is usually implemented at which of the following?
Correct Answer: A
Explanation/Reference:
Explanation:
RAID Levels 3 and 4 function in a similar way. The only difference is that level 3 is implemented at the byte level and level 4 is usually implemented at the block level. In this scenario, data is striped across several drives and the parity check bit is written to a dedicated parity drive. This is similar to RAID 0. They both have a large data volume, but the addition of a dedicated parity drive provides redundancy. If a hard disk fails, the data can be reconstructed by using the bit information on the parity drive. The main issue with this level of RAID is that the constant writes to the parity drive can create a performance hit. In this implementation, spare drives can be used to replace crashed drives.
Incorrect Answers:
B: RAID level 4 is not implemented at bridge level.
C: RAID level 4 is not implemented at channel level.
D: RAID level 4 is not implemented at buffer level.
References:
Krutz, Ronald L. and Russell Dean Vines, The CISSP Prep Guide: Mastering the CISSP and ISSEP Exams, 2nd Edition, Wiley Publishing, Indianapolis, 2004, p. 145