Put your RAID knowledge to the test with our comprehensive quiz. Explore the intricacies of RAID levels, their origins, and their role in data protection.
While RAID remains a cornerstone of data protection, its numerous levels and functions can be complex. Despite emerging alternatives like object storage, RAID continues to evolve and adapt to modern storage needs.
Whether you’re a newcomer or a seasoned professional, this quiz covers essential RAID concepts and their significance in data protection strategies. Challenge yourself to understand the nuances of different RAID levels and solidify your expertise in storage technology.
Table of Contents
Question 1
RAID stands for:
A. Ransomware artificial intelligence defense
B. Redundant array of independent disks
C. Random arrangement of interconnected drives
D. Risk-averse intelligent data
Answer
B. Redundant array of independent disks
Explanation
RAID stands for redundant array of independent disks. It protects data by storing copies in different locations on multiple disks, which can be hard disks or SSDs. Multiple disks also increase the mean time between failures, so using RAID increases fault tolerance.
Independent was not always part of the equation. The technology was first discussed in a 1988 paper, “A Case for Redundant Arrays of Inexpensive Disks (RAID),” by computer scientists from University of California, Berkeley. At the time, they proposed that the development of personal computer drives could provide better performance than existing mainframe disk drives. The RAID advisory board eventually made the change. The “I” in RAID then came to mean independent instead of inexpensive.
Question 2
True or false: There are seven standard RAID levels.
A. True
Answer
A. True
B. False
Explanation
Standard RAID levels are the basic RAID configurations that create data stores from HDDs. These levels are standardized by the Storage Networking Industry Association and are as follows:
RAID 0
RAID 1
RAID 2
RAID 3
RAID 4
RAID 5
RAID 6
The numbers associated with each level are simply meant to identify them, not rank or describe them in any way.
Question 3
Which RAID level is nested?
A. RAID 01
B. RAID 50
C. RAID 10
D. All of the above
E. Only B and C
Answer
D. All of the above
Explanation
Nested RAID levels are the combination of a standard RAID level with RAID 0 to improve performance or redundancy. Nested RAID levels include RAID 01 (0+1), RAID 03 (0+3), RAID 10 (1+0), RAID 50 (5+0), RAID 60 (6+0) and RAID 100 (10+0).
RAID 5 and 6 are two of the most widely used RAID levels. They provide distributed parity across disks and help prevent data loss. Combined with the block-level striping of RAID 0, RAID 50 and 60 perform better and provide more fault tolerance than the standard RAID levels.
RAID 01 and RAID 10 combine the same two RAID levels, but the order of striping and mirroring affects fault tolerance.
Question 4
True or false: All RAID levels use a combination of striping and mirroring data.
A. True
B. False
Answer
B. False
Explanation
Striping data spreads it across multiple drives, which enables multiple disks to access the contents of a file and speeds up writes and reads. The first level, RAID 0, is simply disk striping. Mirroring creates an exact copy of data from one disk and duplicates it to another. This creates redundancy and provides high availability. RAID 1 exclusively mirrors data.
While mirroring creates redundancy, the majority of RAID levels incorporate disk striping.
Some RAID levels use both striping and mirroring, such as RAID 10. However, the costs of storage for duplicate drives adds up, without an improvement in performance. Since striping across multiple disks does not provide redundancy, most RAID levels use a combination of striping and parity.
Dedicating one disk to parity enables the RAID array to determine if the data writes to the disk correctly. Some RAID levels, such as RAID 5, stripe parity across all drives. That way, if one of the disks fails, the array can retrieve the data from any of the remaining disks.
Question 5
True or false: Some RAID levels are obsolete today.
A. True
B. False
Answer
A. True
Explanation
Not all RAID levels are in use or to the degree they once were. Because RAID levels have evolved and adapted with changes in technology, newer RAID levels incorporate features and benefits that have rendered others obsolete. RAID 0 and 1 are the most basic levels, and data protection pros are more likely to recommend a combination of the two, such as RAID 10 or RAID 01. However, if an organization is strictly looking for speedy storage, RAID 0 can provide a bare-minimum level of protection.
That is not the case for RAID 2. It uses Hamming code, rather than parity, to correct errors. Since this code adds complexity and offers no other benefits over parity, RAID 2 is not in use today. RAID 5 has made RAID 3 and 4 mostly obsolete. RAID 7 is a proprietary technology trademarked by Storage Computer Corporation, which no longer exists.
Question 6
What are the benefits of hardware RAID vs. software RAID?
A. Lower costs and easy OS compatibility
B. Does not require a RAID controller
C. No benefits to hardware RAID
D. Faster access speeds and better performance
Answer
D. Faster access speeds and better performance
Explanation
Hardware RAID has been around much longer than software RAID and can provide quicker access to data and better performance. Hardware RAID does not need to use the processing power of its associated computer, since the RAID controller manages disks independently.
Software RAID does not use an external controller, so the computer OS must delegate some of its processing power to the embedded disk controller software. Along with shared processing overhead potentially slowing down the computer, backup admins must also ensure that the RAID controller software is compatible with the OS the organization uses.
The major drawback with hardware RAID is the cost. The external controller and hardware costs can add up, while software RAID uses embedded controller software and does not require additional hardware.
Question 7
True or false: RAID can function as a substitute to data backup.
A. True
B. False
Answer
B. False
Explanation
While RAID can protect data with parity and redundancy, it is not a replacement for a backup strategy. RAID storage has built-in capabilities to prevent data loss and prevent disk failure. RAID does not create point-in-time copies. If a user deletes a file, the RAID array cannot recover it. The only way to recover that file is to restore a data backup created before the deletion.
However, the redundancy and performance of RAID have made it a popular addition to disk-based backups.