When classifying storage by its underlying architecture rather than its transmission protocol, Huawei distinguishes between two main structures. Centralized SAN (Option D) refers to the traditional controller-based array, such as the OceanStor Dorado or OceanStor Hybrid series. In this architecture, all storage resources are managed by a centralized pair or cluster of controllers within a single enclosure system. This provides high stability and specialized data services but has physical limits on the number of controllers and disks it can scale to.

Distributed SAN (Option B) , such as the OceanStor Pacific (formerly FusionStorage), utilizes a scale-out architecture. It aggregates the local storage of multiple standard x86 or ARM servers into a massive, unified virtual storage pool. This architecture eliminates the bottlenecks of centralized controllers, allowing for near-infinite scalability in both performance and capacity by simply adding more nodes. While IP SAN and FC SAN are valid terms, they classify storage by the network protocol used (Ethernet/IP vs. Fibre Channel) rather than the organizational architecture of the storage system itself.

For "Safe City" projects involving massive video surveillance (such as 10,000+ camera streams), Huawei recommends the OceanStor Pacific series (distributed storage). Large-scale video surveillance generates immense volumes of unstructured data that must be written continuously and stored for long periods. A traditional centralized NAS or SAN often faces performance bottlenecks at the controller level when handling thousands of concurrent high-definition video streams.

OceanStor Pacific uses a scale-out architecture that allows performance and capacity to scale linearly. For 10,000 cameras, the system can aggregate the bandwidth of dozens or hundreds of nodes, providing the high throughput required for video ingestion and the massive capacity required for long-term retention. Additionally, OceanStor Pacific supports high-ratio Erasure Coding (EC), which provides better disk utilization (up to 91%) than traditional RAID, significantly reducing the Total Cost of Ownership (TCO) for petabyte-scale surveillance archives.

Direct-Attached Storage (DAS) is a traditional storage architecture where storage devices are connected directly to a host server. Huawei documentation defines the following key characteristics:

Direct Connection (Option C): DAS connects to the server via internal or external interfaces such as SATA, SAS, or SCSI, rather than through a storage network.

No Network Devices (Option A): Because it is a 1-to-1 connection, it does not require Fibre Channel switches or Ethernet switches to facilitate the link between the host and the storage. This makes it simple and cost-effective for small-scale deployments.

Block Storage Services (Option B): Like a SAN, DAS provides block-level access. The server’s operating system manages the file system (NTFS, EXT4, etc.) directly on the provided blocks.

While a server attached to DAS can share its files over a network (becoming a file server), the DAS itself is not a "File Storage Service" (Option D). In Huawei’s hierarchy, file services are the domain of NAS (Network Attached Storage) , which provides shared access to files via protocols like CIFS/SMB or NFS.

In Huawei OceanStor storage systems utilizing RAID 2.0+ and the SmartMatrix architecture, the "write penalty" associated with traditional RAID is mitigated through Full-Stripe Writes. In a partial write (where only some data in a stripe is updated), a RAID 5 setup usually suffers a write penalty of 4 (Reading old data, reading old parity, writing new data, writing new parity).

However, Huawei's controllers utilize a large cache to aggregate incoming data. When enough data is collected to fill an entire stripe (e.g., 8 data chunks plus 1 parity chunk in an 8+1 RAID 5 setup), the system performs a Full-Stripe Write . In this scenario, the system calculates the parity in the CPU/cache and writes the entire stripe to the disks at once. Since no old data or old parity needs to be read from the physical disks before writing, the disk-level write penalty is 0 . This significantly enhances the write performance of hybrid arrays, especially those using mechanical HDDs which are highly sensitive to the latency of extra read/write operations.

This statement is false because it confuses RTO (Recovery Time Objective) with RPO (Recovery Point Objective). In Huawei’s Disaster Recovery (DR) documentation, these two metrics are defined as follows:

RPO (Recovery Point Objective): Refers to the maximum amount of data loss an organization can tolerate, measured in time. It indicates the "point in time" to which data must be recovered (e.g., "we can only lose 1 hour of data").

RTO (Recovery Time Objective): Refers to the duration of time within which a business process must be restored after a disaster. It measures how long the system can be down before the business is significantly impacted (e.g., "the system must be back online within 4 hours").

The question describes the "point in time" (RPO) but labels it as RTO. In a high-availability solution like HyperMetro , the RTO and RPO are both theoretically zero, meaning no data loss and no downtime.

The Huawei OceanStor Dorado series is engineered for 99.9999% availability using multiple layers of reliability. Option A is correct as RAID-TP (Triple Parity) is a unique Huawei feature that uses three parity chunks to tolerate the simultaneous failure of any three SSDs in a disk group. Furthermore, the SmartMatrix full-mesh architecture in high-end models allows the system to remain operational even if seven out of eight controllers in a controller enclosure fail, ensuring extreme service continuity.

Option B is correct because Huawei utilizes Global Wear Leveling to distribute writes across all SSDs to extend their lifespan, and Anti-Wear Leveling to prevent multiple SSDs from reaching their end-of-life simultaneously, which avoids multi-disk failure risks. Option C is correct as the system supports HyperMetro (Active-Active) for both block (SAN) and file (NAS) services, providing zero RTO and RPO across sites. Option D is correct because Dorado supports high-reliability disk enclosure connection technologies; in a multi-enclosure setup, the system can tolerate the failure of an entire disk enclosure without data loss by using intelligent data distribution across different enclosures.

Huawei OceanStor Dorado high-end models (such as the 18000 series) utilize the SmartMatrix 4.0 architecture to provide industry-leading resilience. Option A is correct because these models can tolerate the failure of an entire controller enclosure (containing 4 controllers) without interrupting services, as the other enclosure in the cluster continues to handle all I/O. Option B is correct because Dorado features a Symmetric Active-Active design where any LUN is not owned by a specific controller; instead, any controller in the cluster can directly access any LUN, eliminating the performance bottleneck caused by traditional ALUA (Asymmetric Logical Unit Access) and ensuring load balancing.

Option C is correct as Huawei employs Smart Disk Enclosures equipped with their own CPU and memory. These enclosures can offload tasks like data reconstruction (RAID rebuilds) from the main controllers, significantly speeding up recovery times and reducing the performance impact on host I/O during a disk failure. Option D is incorrect because OceanStor Dorado is an All-Flash array; it does not support HDDs and therefore does not perform tiering between flash and mechanical media (which is a function of the OceanStor Hybrid Flash series).

Storage Area Network (SAN) storage is designed to provide block-level data access to servers, appearing to the operating system as a locally attached hard drive. Huawei OceanStor SAN solutions (both FC-SAN and IP-SAN) are optimized for high-performance, low-latency applications.

Databases (Option C) , such as Oracle, SQL Server, and DB2, are primary use cases for SAN storage because they require high IOPS and low latency for transactional processing. The block-level access allows the database management system to have granular control over data placement and caching. VMware virtualization (Option B) is another core scenario. SANs provide the shared storage necessary for advanced features like VMotion, High Availability (HA), and Distributed Resource Scheduler (DRS). In these environments, multiple ESXi hosts connect to a centralized SAN to access VMFS (Virtual Machine File System) volumes. While Option A (Big Data) and Option D (File Sharing) often use Distributed Storage (OceanStor Pacific) or NAS, the high-concurrency, structured nature of Databases and Virtualization makes them the definitive scenarios for SAN.