The dual-controller storage system generally contains a mirror channel, and data written to the storage system cache will be written through the…

The statement is correct. In a dual-controller storage system, high availability is a primary design goal. To achieve this, a mechanism called cache mirroring is employed to protect data that has been written by a host but has not yet been committed to permanent disk storage. When a host sends a write request, the data is first written to the cache of the active controller. Immediately after, this data is copied over a dedicated high-speed internal link, known as the mirror channel or interconnect, to the cache of the peer (standby) controller. The storage system only sends a write acknowledgment back to the host after the data has been successfully secured in the caches of both controllers. This ensures that if the primary controller fails, no data is lost, as a consistent copy exists in the peer controller's cache, ready to be taken over and destaged to the disks.

This is a "TRUE OR FALSE" question. The provided statement is factually correct according to standard high-availability storage architecture principles. Therefore, the "False" option is incorrect.

1. Huawei Certified ICT Associate - Storage V5.0 Training Material (Document ID: H13-611).

Reference Section: Chapter 2

"Storage System Hardware and Software Architecture

" subsection on "Reliability Technologies."

Content: The official training material explains that in a dual-controller configuration

"the caches of the two controllers mirror data for each other. When data is written to the cache of one controller

it is also written to the cache of the other controller through the mirroring channel. If one controller is faulty

the other controller can take over services

ensuring data consistency and service continuity." This directly validates the statement in the question.

2. Patterson

D. A.

& Hennessy

J. L. (2017). Computer Organization and Design: The Hardware/Software Interface (5th ed.). Morgan Kaufmann.

Reference Section: Chapter 5

"Large and Fast: Exploiting Memory Hierarchy

" section on "Dependability

Reliability

and Availability."

Content: While not specific to Huawei

this foundational computer architecture text discusses principles of redundant systems. It describes how redundant controllers with mirrored

non-volatile write caches are a standard industry practice to achieve high availability (HA) in storage arrays. The concept of mirroring data between controller caches before acknowledging a write is presented as a key technique to tolerate a single controller failure without data loss.

3. University of California

Berkeley. EECS 151/251A

Introduction to Digital Design and Integrated Circuits

Lecture 20: "I/O Systems."

Reference Section: Slides discussing Storage Area Networks (SANs) and high-availability storage controllers.

Content: University courseware on computer systems and I/O architecture frequently covers the design of enterprise storage. These materials explain that dual-controller architectures are the norm for fault tolerance. The lecture notes detail the write I/O path

specifying that a write-back cache must be mirrored to a second controller over a high-speed interconnect to protect "in-flight" data

thus preventing data loss if a controller fails before the data is written to disk.