Dual-Controller Storage System Working Modes and Failover

H13-611 By islever Editorial Last updated

Huawei Intelligent Storage Products

Short answer

ABCD All statements accurately describe dual-controller storage system behaviors, including active-standby and active-active modes, failover efficiency, and operational states.

Question

Which statements are true about a dual-controller storage system? (Choose all that apply.)
  1. There are two working modes: active-standby and active-active. Correct Answer
  2. In active-standby mode, if one controller is faulty, services are not affected. Correct Answer
  3. When one controller is faulty, the service failover in active-active mode is more efficient than that in active-standby mode. Correct Answer
  4. In active-standby mode, only one controller works at a time. Correct Answer

Key Takeaways

The main trap is confusing the failover efficiency between active-standby (which has an I/O pause during switchover) and active-active (which offers seamless load redistribution).

This question tests knowledge of dual-controller storage systems, specifically comparing active-standby and active-active working modes and their respective failover characteristics.

Common mistake: Many candidates might incorrectly assume that active-standby failover is faster or that both controllers work simultaneously in active-standby mode, leading them to miss options B and D.

Expert Analysis

Active-standby mode: Only one controller actively processes I/O at a time. The other is in hot standby, ready to take over if the active fails. Therefore, D is true.

Failover in active-standby: If the active controller fails, the standby takes over. This causes an I/O pause while the takeover happens, but services are not permanently affected. Thus, B is true.

Active-active mode: Both controllers process I/O simultaneously. If one fails, the other handles all traffic without needing a full takeover sequence from a cold state. Failover is more efficient than active-standby because there is no single point of failure bottleneck and load balancing continues. Thus, C is true.

A is also true as these are the two standard working modes.

Exam Strategy

When analyzing storage controller questions, always distinguish between 'active-standby' (one active, one idle/ready) and 'active-active' (both processing). Remember that active-standby failover involves a brief I/O pause, while active-active provides better fault tolerance and efficiency.

Frequently Asked Questions

What is the difference between active-standby and active-active modes?

In active-standby, one controller handles all I/O while the other waits. In active-active, both controllers share the I/O load simultaneously for better performance and redundancy.

Is service interrupted during failover in active-standby mode?

Yes, there is typically a brief I/O pause during the switchover from the failed active controller to the standby controller, but services are not permanently affected.

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Community Votes

A
34%
C
33%
D
33%

34% of anonymous learners picked answer A. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 1 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 1

  1. 10c5cfe 👍 1
    if active controller fails there is an i/o pause while switchover

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