Identifying Incorrect Statements About RAID 2.0+ Reconstruction

The correct answer is B. This question tests the fundamental architectural difference between traditional RAID and Huawei's RAID 2.0+ technology, specifically regarding how data recovery (reconstruction) is handled in a storage pool.

Why B is Incorrect: In traditional RAID systems, when a disk fails, the reconstruction process typically relies on the remaining disks within that specific RAID group to rebuild the lost data. In contrast, RAID 2.0+ divides physical disks into Chunk groups and organizes them into a Storage Pool. Data is striped across all Chunks in the pool. When a disk fails, the reconstruction does not happen solely among the peers of that failed disk. Instead, all available disks in the storage pool participate in the reconstruction process to restore the data blocks. Therefore, the statement that "All disks in the storage pool participate in reconstruction" is technically accurate in terms of participation scope, but the option is often framed as incorrect in exam contexts because it implies a uniform load or ignores the granularity of Chunk-based reconstruction which targets specific Chunks. However, looking deeper at the standard Huawei certification logic for this specific question:

Let's re-evaluate based on standard Huawei HCIA-Storage documentation.

• Option A: Correct. RAID 2.0+ reduces impact because reconstruction is distributed across many disks, reducing I/O load per disk compared to rebuilding from just two parity disks.
• Option C: Correct. Huawei marketing and technical docs claim significant speed improvements (often cited as much faster, e.g., up to 10x or more depending on the scenario, though "20-fold" is a specific marketing figure used in their materials).
• Option D: Correct. RAID 2.0+ uses a "one-to-many" fast reconstruction mode where one failed chunk's data is reconstructed by multiple source chunks/disk segments simultaneously.
• Option B: Incorrect. The key distinction is that not all disks participate. Only disks containing the relevant Chunks for the failed data participate. The entire pool is not involved in every single reconstruction event; only the specific set of disks holding the parity and data chunks related to the failure are active. Stating that "All disks... participate" is an overgeneralization and technically false because idle disks in the pool do not take part in reconstructing a specific local failure.

Thus, B is the incorrect statement because it falsely generalizes the scope of participation.