Best RAID Configuration for Maximum Redundancy with Four Disks

SK0-005 By islever Editorial Last updated

Short answer

B RAID 1

Question

A systems administrator needs to create a data volume out of four disks with the most redundancy. Which of the following is the best solution?
  1. RAID 0
  2. RAID 1 Correct Answer
  3. RAID 5
  4. RAID 6

Key Takeaways

The exam tests the distinction between theoretical maximum parity failures and practical mirroring capabilities; the trap is assuming RAID 6 always provides more redundancy than RAID 1 regardless of disk count.

This question tests the understanding of RAID redundancy levels versus disk count. Community consensus highlights that while RAID 6 is standard for multi-disk arrays, RAID 1 (mirroring) offers higher fault tolerance when using four disks.

Common mistake: Option D (RAID 6) is the most common wrong answer because candidates assume it is the highest redundancy level generally, forgetting that RAID 1 mirrors all data across all disks in this specific 4-disk configuration.

Expert Analysis

Why the Answer Is Correct

RAID 1 creates a mirror of the entire dataset on each drive. With four disks configured as RAID 1 (often implemented as multiple mirrored pairs or full system mirroring depending on the controller), every piece of data exists on all four drives. Therefore, the array can survive the failure of up to three disks without data loss.

Why the Other Options Are Wrong

RAID 0 offers no redundancy. RAID 5 can tolerate only one disk failure. RAID 6 can tolerate two disk failures. While RAID 6 is robust, it cannot match the fault tolerance of a fully mirrored setup where every disk holds a complete copy of the data.

Community Comment Notes

Commenters correctly point out that RAID 6 allows only 2 failures, whereas RAID 1 with 4 disks allows 3 failures. This mathematical difference makes RAID 1 the technically superior choice for 'most redundancy' in this specific constraint, despite RAID 6 being more space-efficient.

Exam Strategy

Always evaluate redundancy based on the number of simultaneous failures allowed relative to the total disk count. Do not automatically select the highest-numbered RAID type; calculate the actual fault tolerance for the given hardware configuration.

Community Votes

B
75%
D
25%

75% of anonymous learners picked answer B. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 4 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 4

  1. [Removed] 👍 2
    D. RAID 6. RAID 6 offers the highest level of redundancy among the options listed. In RAID 6, data is striped across all disks in the array, similar to RAID 5. However, in addition to striping, RAID 6 also includes two sets of parity data distributed across all disks. This means that RAID 6 can tolerate the failure of up to two disks in the array without losing data, providing an extra level of protection compared to RAID 5.
  2. [Removed] 👍 2 Answered B
    Definitely not D. RAID6 allows only 2 disks to fail, while RAID1 in this scenario, with 4 disks, allows 3 of them to fail. Hence RAID1 is more redundant. Answer is B
  3. Ronn_Burgandy 👍 1 Answered B
    B. The most redundancy would be raid 1. This would mirror every drive in the raid allowing up to 3 drives to fail. Raid 6 allows 2 drives to fail. So the “best” redundancy would be raid 1 even though in a real server an admin would more likely choose raid 5/6 to have more space then only a single drive.
  4. fluke92 👍 1 Answered D
    Explanation: RAID 6 provides the most redundancy while using four disks by implementing dual parity. This allows the system to tolerate up to two simultaneous drive failures without data loss, which is the highest level of redundancy among the options provided.

Reader comments & corrections

No reader corrections yet — spotted an error or have a note? Share it below.

Log in to comment, report an error, or add a note about this question.

Practice All SK0-005 Questions

Access 135 questions with complete answers and detailed explanations.

View Full SK0-005 Practice Test →

← Back to SK0-005 Study Guide