H19-308_V4.0 HCSA-Presales-Storage V4.0 Question and Answers

Huawei’s 3DC (Three-Data-Center) solution is designed for high-level business continuity, typically involving a local HA site and a remote DR site. The documentation supports three main topological configurations to meet different reliability and performance needs:

Cascading Network (Option B):Site A (Production) replicates to Site B (Local DR), and Site B then replicates to Site C (Remote DR). This reduces the pressure on the production site (Site A) as it only manages one replication link.

Parallel Network (Option C):Site A replicates directly to both Site B and Site C simultaneously. This provides better protection for the data at Site C, but increases the load and bandwidth requirements on Site A.

DR Star Network (Option A):This is a specific variant of the multi-site protection architecture used in Huawei'sHyperMetro + Remote Replicationscenarios. It typically combines an active-active setup between Site A and B with an asynchronous link to Site C, ensuring that even if two sites fail, the third contains a survivable copy of the data.

This statement is false because Huawei's new-generation OceanStor hybrid flash storage features a converged (Unified) architecture that supports Native NAS capabilities directly within the storage controllers. In older storage generations or with competitors, an external "NAS Gateway" or "Filer" was often required to provide file services on top of block storage.

Huawei’sHyperMetro for NASis a gateway-free active-active solution. The file systems are managed natively by the storage OS (OceanStor OS), allowing both SAN and NAS services to benefit from the same high-availability features. By eliminating the need for an external gateway, Huawei simplifies the network topology, reduces hardware costs (TCO), and minimizes latency by removing an extra processing hop for file data. This native integration allows for seamless cross-site active-active deployments for file protocols like CIFS/SMB and NFS, just as it does for block protocols.

Huawei OceanStor Pacific is a distributed scale-out storage system optimized for mass unstructured data (File, Object, HDFS). While it provides robust "always-on" service capabilities, Option A is incorrect as it refers to a specific feature of centralized unified storage arrays like the OceanStor Dorado series. OceanStor Dorado is marketed as providing the industry's only "Active-active solution for SAN and NAS" within a centralized architecture.

In contrast, OceanStor Pacific ensures service continuity through distributed mechanisms:

Fast Failover (Option B):Technologies such as multi-module concurrent service takeover enable services on a faulty node to be taken over within 10 seconds, minimizing RTO.

HyperGeoMetro (Option C):This feature provides multi-replica cross-site active-active protection for object storage, allowing data to be accessed and modified at multiple sites simultaneously.

HyperGeoEC (Option D): This is a cross-site Erasure Coding (EC) multi-active solution that provides high reliability and space utilization for large-scale deployments.

Because OceanStor Pacific is designed for distributed unstructured workloads rather than integrated SAN/NAS block-and-file convergence in the traditional sense, Option A is the outlier.

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 aFull-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-levelwrite 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.

Huawei OceanStor NAS systems provide a comprehensive Audit Log feature to track user activities for security and compliance purposes. This feature records metadata related to how files and directories are accessed and manipulated over the SMB or NFS protocols.

According to the Huawei technical reference, the audit mechanism captures a wide range of events, including:

File Opening (Option D):Records when a user accesses a file, including the timestamp and user ID.

File Modification (Option B):Tracks changes made to the content of a file.

File Renaming (Option A) and Deletion (Option C):Records structural changes to the file system, which is critical for identifying potential data theft or accidental loss.

By analyzing these logs, administrators can reconstruct the history of file operations to determine "who did what and when." This is a key component of Huawei’s data security framework, helping organizations meet internal auditing requirements and external regulatory standards.

NVMe over Fabrics (NVMe-oF) using the RoCE v2 (RDMA over Converged Ethernet) protocol is a high-speed communication technology supported by Huawei OceanStor Dorado systems. Option B is correct because RoCE v2 utilizes RDMA, which allows data to be transferred directly from the memory of one computer to another without involving the CPU of either system. This significantly reduces latency and CPU overhead compared to traditional iSCSI.

Option C is correctbecause RoCE v2 requires a "Lossless Ethernet" environment to function correctly. Traditional Ethernet (Option A) is a "best-effort" delivery system that allows for packet drops during congestion; however, RDMA protocols are highly sensitive to packet loss. To support RoCE v2, the network must implement Data Center Bridging (DCB) features like Priority Flow Control (PFC) and Enhanced Transmission Selection (ETS) to ensure a zero-packet-loss environment. Regarding cost (Option D), RoCE v2 often leverages existing Ethernet infrastructure, making it generally more cost-effective than deploying a dedicated Fibre Channel (FC) fabric, which requires specialized HBAs and FC switches.

Huawei’s HyperReplication technology is designed to provide robust data redundancy across geographically separated storage systems. According to official technical specifications, Huawei storage supports two primary replication modes:

Synchronous Remote Replication (Option A):In this mode, data is written to both the local and remote storage systems simultaneously. The host receives a write-completion acknowledgement only after the data is successfully stored in both locations. This ensures zero data loss (RPO = 0) but is sensitive to network latency and is typically limited to distances within 100km to 300km.

Asynchronous Remote Replication (Option C):Data is first written to the local storage, and the host receives an immediate acknowledgement. The data is then synchronized to the remote site at defined intervals or based on specific triggers. This mode is not limited by distance and has minimal impact on application performance, though it carries a risk of minor data loss (RPO > 0).

Terms like "Semi-synchronous" or "Semi-asynchronous" (Options B and D) are not standard replication modes in the Huawei OceanStor architectural framework.

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.

Huawei’s SmartQuota feature allows administrators to manage storage consumption at the directory, user, or user-group level using three types of thresholds:

Hard Quota (800 GB):This is a strict limit. Once the used capacity reaches this value, the storage system will immediately prevent any further write operations to that directory. Therefore, Option Dwilloccur.

Soft Quota (700 GB):This is a flexible limit combined with a grace period. When the limit is exceeded, the system issues an alarm butcontinues to allow data writesuntil the grace period expires or the hard quota is reached. Therefore, Option B willNOToccur.

Advisory Quota (600 GB):This is purely for monitoring and reporting. When reached, the system simply triggers an administrative alarm or notification; itnever restricts data writes. Therefore, Option C willNOToccur.

Option A is also correct because the directory is part of a 1 TB file system; it can never exceed the physical size of its parent container. Thus, only B and C are the actions that "will NOT occur."

This statement is true according to Huawei’s storage networking fundamentals. iSCSI (Internet Small Computer System Interface) encapsulates SCSI commands into TCP/IP packets for transmission over standard Ethernet networks. Because it leverages the universal TCP/IP stack, iSCSI can operate across existing routers, switches, and long-distance WAN links without requiring the specialized, expensive hardware associated with Fibre Channel (such as FC switches and Host Bus Adapters).

This reliance on standard Ethernet infrastructure provides iSCSI with superiorscalability and flexibility. For example, iSCSI allows storage to be accessed over any distance where an IP connection exists, which is inherently simpler than the complex "FCIP" tunneling required to extend FC over long distances. Additionally, as Ethernet speeds continue to evolve rapidly (10GbE to 25GbE, 100GbE, and beyond), iSCSI can easily scale its performance by upgrading standard networking components. While Fibre Channel often offers lower latency and better raw performance in dedicated local environments, the ease of expansion and integration into existing IP networks makes iSCSI the more scalable choice for broad data center environments.

Huawei’s object storage solution (OceanStor Pacific/OBS) is designed for massive scalability and high availability across geographic boundaries. Option C is correct because the Global Namespace feature abstracts the physical location of data, allowing users to access objects via a single URL/endpoint regardless of which Data Center or Availability Zone (AZ) the data physically resides in. This simplifies application development and data management at scale.

Options A and B are correctas the architecture supports multi-regional deployment. Data can be replicated between regions to ensure disaster recovery and data sovereignty. Unlike traditional SAN/NAS replication which is often limited by latency-sensitive synchronous protocols, object storage utilizes asynchronous transfer mechanisms optimized for the HTTP/S3 protocol. This leads toOption D being correct; because object storage replication is typically asynchronous and handles high latency well, sites can be separated by thousands of kilometers, making it an ideal solution for global data distribution and remote site backup.

While it is technically possible to use a gateway to provide object interfaces over traditional storage, Huawei documentation explicitly states that this is not the mainstream delivery mode for the future of cloud-native data. Traditional SAN or NAS architectures are built on hierarchical file systems or block volumes, which face significant metadata performance bottlenecks and scalability limits when forced to handle billions of objects.

The "mainstream" and recommended approach by Huawei isNative Object Storage, such as that found in theOceanStor Pacificseries. Native object storage is built on a flat architecture from the ground up, allowing for massive horizontal scalability, a global namespace, and superior metadata handling through distributed indexing. Using a gateway is considered a legacy transition method or a "bridge" solution, but it lacks the efficiency, performance, and durability required for modern big data, AI, and cloud-native applications that natively use the S3 protocol.

Huawei’s data protection solutions, particularly the OceanProtect and BCManager suites, support a wide range of backup targets to accommodate various Recovery Time Objectives (RTO) and Recovery Point Objectives (RPO).

Disk (Option C):This is the most common modern backup media (Disk-to-Disk or D2D), offering fast backup and recovery speeds. Huawei's OceanProtect is a dedicated high-speed disk-based backup storage.

Tape Library (Option D):Traditionally used for long-term archiving (D2D2T), tape remains a cost-effective and reliable "offline" storage medium for compliance and disaster recovery.

Disc (Option A):Optical discs (like Blu-ray) are used in specific archival scenarios where "Write Once" (WORM) physical media is required for regulatory purposes.

Cloud (Option B):Modern Huawei solutions supportBackup to Cloud, where data is deduplicated, compressed, and sent to an off-site object storage provider (like Huawei Cloud OBS) for cost-effective disaster recovery without the need for a physical secondary site.

Huawei OceanStor Dorado utilizes RAID 2.0+ block virtualization technology, which supports Dynamic RAID Reconstruction. In a traditional RAID environment, if a disk fails, the RAID group continues to operate in a "degraded" mode until the disk is replaced. However, in Dorado's RAID 2.0+, the system uses a distributed spare space policy where spare capacity is spread across all disks in the pool.

When one SSD fails in a storage pool originally configured with RAID 6 (7 data chunks + 2 parity chunks), the system identifies that it no longer has enough physical disks to maintain a 7+2 stripe width. To maintain the same level of protection (dual parity) while utilizing the remaining 8 disks, the system dynamically adjusts the RAID policy for new writes and reconstructed data toRAID 6 (6+2). This ensures that the data remains protected by two parity chunks even with a reduced disk count. This "shrinkage" of the stripe width allows the system to remain in a "healthy" protected state rather than staying in "degraded" mode indefinitely.

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 likeHyperMetro, the RTO and RPO are both theoretically zero, meaning no data loss and no downtime.