Which of the following characteristics about RAID is incorrect?
A. Expanded storage capability
B. Fast access speed
C. Highly reliable
D. One high-capacity hard disk drive
The Correct Answer and Explanation is:
The correct answer is D. One high-capacity hard disk drive.
Explanation:
RAID (Redundant Array of Independent Disks) is a data storage technology that combines multiple physical disk drives into a single logical unit to improve performance, reliability, and storage capacity. The incorrect characteristic listed is “One high-capacity hard disk drive” because RAID, by its very nature, involves multiple disk drives, not just a single high-capacity disk.
Here’s a detailed breakdown of the other options:
- A. Expanded storage capability: RAID can indeed provide expanded storage capability. By combining multiple hard drives into an array, it allows for larger storage capacity than individual drives. For instance, RAID configurations like RAID 0 or RAID 5 can aggregate storage from multiple disks, enhancing the total available space.
- B. Fast access speed: One of the main benefits of RAID is its ability to improve data access speed. RAID configurations like RAID 0 (striping) improve read and write speeds by distributing data across multiple drives. RAID 10 (a combination of RAID 1 and RAID 0) also offers high-speed data access alongside redundancy. However, not all RAID configurations prioritize speed equally—RAID 5 and RAID 6, for example, prioritize data redundancy over sheer performance.
- C. Highly reliable: RAID is also known for improving data reliability and fault tolerance. Many RAID levels (such as RAID 1 and RAID 5) include redundancy, which means data is mirrored or parity data is stored, allowing the system to survive the failure of one or more drives without data loss. RAID 1, for example, mirrors data across two disks, so if one fails, the other contains an identical copy of the data.
Why “One high-capacity hard disk drive” is incorrect:
RAID inherently requires more than one disk drive. A single high-capacity hard disk drive would not provide the fault tolerance, performance, or storage expansion benefits that RAID offers. While a single large disk might hold significant data, it would not improve data access speeds or provide redundancy—key features that RAID configurations like RAID 1, RAID 5, and RAID 10 offer.
In conclusion, the fundamental feature of RAID is the use of multiple disks, making option D incorrect.