Host Multipathing Software Benefits: Redundancy and Logical Consistency
Short answer
AC Multipathing software improves link reliability by providing redundancy against single-link failures and avoids logical errors by presenting multiple paths as a single device to the operating system.
Question
Key Takeaways
The question tests the distinction between host-side software responsibilities (redundancy and path abstraction) versus storage-side administrative tasks (LUN mapping and physical connectivity).
Learn why installing multipathing software on a host prevents single-link failures and resolves logical errors when accessing shared LUNs via multiple paths.
Common mistake: Candidates often confuse Option D (LUN mapping) with multipathing. Mapping is a storage array configuration task that grants access, whereas multipathing handles how the host sees and manages those already-granted paths.
Expert Analysis
Multipathing software, such as Huawei's UltraPath or standard OS multipathers, is installed on the host to manage multiple physical paths between the server and the storage array. Its primary functions are to provide high availability through redundancy and to optimize performance through load balancing.
Option A is correct because multipathing creates redundant paths. If one physical link (HBA port, cable, or switch) fails, the software automatically redirects I/O traffic to an available path, preventing a single link failure from causing system downtime or data loss. This directly improves link reliability.
Option C is also correct. Without multipathing software, an operating system might see multiple independent paths to the same Logical Unit Number (LUN) as separate, distinct disks. This can lead to logical errors, such as filesystem corruption, if multiple paths write simultaneously or if the OS attempts to mount the same volume multiple times. Multipathing software presents these multiple physical paths as a single virtual device to the OS, resolving this ambiguity and preventing logical conflicts.
Options B and D are incorrect because they describe infrastructure configuration tasks performed on the storage array or SAN switches, not the host software. Setting up physical connections (B) involves cabling and switch zoning, while mapping a LUN to a host (D) is an administrative action performed in the storage array management interface to grant access rights. These steps precede or occur independently of the installation of multipathing software on the host.
Exam Strategy
When analyzing storage protocol questions, strictly categorize actions into 'Storage Array/SAN Switch' vs. 'Host'. Administrative actions like LUN masking/mapping (Option D) and physical setup (Option B) belong to the infrastructure side. Host-side software always focuses on visibility, redundancy, and path management logic.
Frequently Asked Questions
Does multipathing software map LUNs to the host?
What happens if multipathing software is not installed?
Community Votes
50% of anonymous learners picked answer A. Votes are pick records left by other test-takers — they are not the verified answer.
Discussion 2 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 2
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ThaeGyii 👍 1B & D: Setting up physical connections and mapping (or masking) a LUN to a host are administrative tasks configured on the storage area network (SAN) switch and the storage array itself, not functions performed by installing multipathing software on the host.
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Yamensa 👍 1This is the correct answer
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