11. Answer the following regarding the RAID levels: a. We use RAID 5 instead of

Question

11. Answer the following regarding the RAID levels:

a. We use RAID 5 instead of RAID 4. In what way is RAID 5 better than RAID 4?

b. A home computer users wishes to select some form of RAID for both improved storage access and some amount of redundancy but does not want a RAID 1 cabinet. Which would you recommend and why?

c. Assume a RAID cabinet consists of 6 independent drives. Assume the same surface on the first and last drives both fail. Which RAID levels could potentially recover from the two failures? Explain.

Explanation / Answer

a)

RAID-4 is not in common use, because every single write operation has to write to the parity disk, which leads to bottlenecking. In addition, read operations do not use the parity disk, which slightly reduces read throughput, as n-1 drives are involved instead of n. RAID-5 is similar to RAID-4 but varies which drive holds the parity data for each block, thus relieving the bottleneck, and enabling all drives to be used simultaneously for reading.

c)

While RAID-5 protects against a single drive failing and can rebuild it,

RAID-6 uses two different sets of parity calculations and can rebuild an array even with two failures at same time (what's known as N+2 redundancy). RAID-6 requires at least 4 drives - at least two for data, and two for the parity information.

b)

Related Questions

Navigate

• Browse (All)
• Browse 1
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.