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

This statement reflects the architectural evolution of Huawei OceanStor systems. The Small Computer System Interface (SCSI) protocol was designed decades ago for mechanical drives (HDDs). It uses a single command queue with a depth of 32 commands, which was sufficient for the physical limitations of rotating platters and moving heads.

In contrast,Non-Volatile Memory express (NVMe)was designed specifically for flash media. It replaces the legacy SCSI stack to eliminate bottlenecks. NVMe supports up to 64,000 queues, each with 64,000 commands, allowing for massive parallelism. Huawei OceanStor Dorado (All-Flash) systems utilizeEnd-to-End NVMe(from the SSD to the controller, and from the controller to the host via NVMe-oF) to achieve microsecond-level latency. While modern flash arrays can still use SCSI (via FC or iSCSI) for compatibility, the full performance potential of an all-flash array is only realized through NVMe. Therefore, in modern storage design, SCSI is the legacy standard for HDDs/Hybrid arrays, while NVMe is the optimized standard for All-Flash arrays.

Huawei’s OceanProtect backup storage solution is designed for the F2F2X (Flash-to-Flash-to-Anything) era. This concept represents a shift from the traditional Disk-to-Disk-to-Tape (D2D2T) backup model to a faster, more flexible architecture.

In the F2F2X model, data is backed up from the primary Flash storage (Dorado) to the dedicated backup Flash storage (OceanProtect) to ensure rapid backup and recovery. The "X" in F2F2X officially stands for "Anything," representing the final destination for long-term data retention or off-site disaster recovery. In the context of Huawei’s pre-sales training and hybrid cloud strategy,Cloud (Option A)is the primary "X" promoted to customers. By replicating backup copies to a public or private cloud (such as Huawei Cloud OBS), organizations can achieve cost-effective, long-term archiving and off-site protection without managing physical tape libraries. While "X" can technically be tape or another disk, the strategic emphasis for the new-gen solutions is the seamless integration with cloud ecosystems.

Huawei’s Multi-protocol Lossless Interworking is a standout feature of the OceanStor Pacific series, allowing one copy of data to be shared across different protocols (File, Object, HDFS).

No Semantic or Performance Compromise (Option B):Historically, protocol conversion (e.g., using a gateway) led to performance loss or "semantic loss" where certain file attributes or object tags were dropped. OceanStor Pacific implements native support for multiple protocols at the metadata level, ensuring full semantic compatibility and high-speed access regardless of the protocol used.

Zero Data Copy (Option C):This feature allows one piece of data to be written via one protocol (e.g., ingested via S3) and read via another (e.g., analyzed via HDFS) without moving or copying the data to a separate system. This eliminates "data silos" and greatly improves data processing efficiency.

Gateway-free (Option D):Because the interworking is native to the storage OS, no external protocol gateways are required. This simplifies the management architecture and reduces the hardware footprint.

Option A is incorrectbecause documentation generally advises against mixing structured (Database) and unstructured data in the same pool for optimal performance, though the system is primarily optimized for unstructured workloads.

This statement is true as it describes a core architectural component of the Huawei SmartMatrix fully-interconnected design. In the new-generation OceanStor hybrid flash systems, multiple controllers within a cluster must communicate at extremely high speeds to synchronize cache data and manage metadata across the entire storage pool.

To achieve the low latency required for these operations, Huawei utilizesRDMA (Remote Direct Memory Access)for controller interconnection. RDMA allows one controller to access the memory of another controller directly, bypassing the operating system's kernel and reducing CPU overhead. This high-speed back-end interconnection (often operating at 100 Gbps or higher) ensures that data can be mirrored between controllers almost instantaneously, which is critical for supporting symmetric active-active services and maintaining 99.9999% availability. By using RDMA, Huawei can deliver "flash-like" performance even in hybrid arrays by ensuring that the architectural bottlenecks of traditional controller communication are eliminated.

Huawei’s SmartThin technology is a thin provisioning feature that allows storage administrators to allocate more logical capacity to servers than is physically available in the storage pool. Traditionally, "thick provisioning" reserves the entire capacity of a LUN the moment it is created, leading to significant "stranded" or wasted space if the application does not immediately use it.

With SmartThin, the storage system only consumes physical blocks when data is actually written to the disk. This "on-demand" allocation ensures that physical resources are shared across multiple LUNs more efficiently. For example, a 10 TB LUN might be presented to a database, but if the database only contains 2 TB of data, only 2 TB of physical space is consumed. This significantly improves theStorage Resource Utilization Rateand reduces the Total Cost of Ownership (TCO) by delaying the need to purchase additional physical disks until the actual consumed capacity approaches the physical limits of the array.

In Huawei OceanStor NAS systems, data consistency and integrity are maintained through a mechanism known as File Locking. When User A opens a file for modification (a write operation), the storage system applies a "Write Lock" or an "Exclusive Lock" to that specific file. This lock prevents other users from performing any actions that would alter the file's metadata or content, as these concurrent changes would lead to data corruption or "lost updates".

Consequently,File deletion (Option A),File modification (Option C), andFile renaming (Option D)are all blocked because they require write-level access or changes to the file system's directory structure that conflict with the active lock held by User A. However,File reading (Option B)is generally permitted unless User A has specifically requested an exclusive lock that bars all access. In standard CIFS/SMB and NFS configurations used by Huawei, multiple users can read a file while one user is writing, ensuring that information remains accessible without compromising the integrity of the file being updated.

Huawei OceanStor Dorado supports Non-disruptive Upgrade (NDU), which allows the storage system’s software (firmware) to be upgraded while services are running. In a traditional storage environment, an upgrade might require a system reboot or cause a failover that interrupts I/O for several seconds or minutes. However, Dorado's NDU leverages the multi-controller architecture and advanced caching mechanisms.

During an NDU, the system upgrades controllers one by one or in batches. While one controller is being upgraded and rebooted, its workloads are transparently taken over by other active controllers in the same cluster. Because the host-side multipathing software handles the path failover and the storage system maintains cache mirroring, the application servers experience zero downtime and negligible performance impact. This feature is essential for mission-critical environments that require 24/7 availability and cannot afford scheduled maintenance windows for routine software updates.

This statement is false because RAID 0 and Mirroring (RAID 1) are fundamentally different concepts in Huawei storage technology. As defined in the Huawei technical manual, RAID 0 is "Striping." It breaks data into chunks and spreads them across multiple disks to increase performance. It has no redundancy.

"Mirroring" is the terminology specifically used for RAID 1. In a RAID 1 configuration, the system writes the exact same data to two separate physical disks simultaneously. This creates a 100% redundant copy (a mirror). If one disk fails, the other continues to provide data, ensuring zero downtime and no data loss. Huawei'sRAID 2.0+ virtualization technologycan implement striping and mirroring across different "chunks" or "extents" within a storage pool, but it maintains the technical distinction: RAID 0 is for performance through striping, while mirroring is for reliability through duplication. Therefore, characterizing RAID 0 as a mirroring technology is a technical inaccuracy.

This statement is false because the Air Gap isolation zone is one of the most critical components of the Huawei OceanProtect ransomware protection solution. Huawei provides a comprehensive "four-layer" protection framework for data resilience, where Air Gap technology serves as the final, most secure layer.

TheAir Gapfeature creates a security isolation zone for backup data. Under normal operations, the replication link between the production backup storage and the isolation zone storage is physically or logicallydisconnected(the "gap"). The link only opens during a specific, scheduled window to replicate "clean" data from the production site to the isolation zone, and it is immediately closed once replication is finished. This ensures that even if ransomware compromises the main network and production storage, the data in the Air Gap isolation zone remains "invisible" and unreachable to the attacker. Combined with secure snapshots and WORM, this allows organizations to recover their business from an uninfected copy of the data, making Air Gap a core supported feature of the OceanProtect portfolio.

Huawei documentation highlights several key advantages of object storage for modern data requirements. Option A is correct because object storage primarily uses RESTful APIs (HTTP/HTTPS), which are firewall-friendly and accessible globally over the internet, unlike NFS/CIFS/SMB which are generally restricted to local area networks (LANs).

Option B is correctbecause object storage allows forextensible metadata. Users can attach custom tags to objects, enabling powerful data searching and automated lifecycle management without needing an external database to track file attributes.Option D is correctbecause object storage uses aflat namespacerather than the tree-shaped directory structure of NAS. In a flat structure, adding more nodes to the system does not increase the complexity of data retrieval, allowing for nearly infinite horizontal scalability. Option C is incorrect in this context because the tree-shaped directory is actually a limitation of NAS that causes performance degradation at high scales, whereas object storage avoids this hierarchy to improve expansion capabilities.

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.

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.

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 ascale-out architecturethat 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.

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."

The statement accurately describes Huawei’s Adaptive Data Locality Rearrangement technology used in OceanProtect systems. Backup data is often deduplicated and compressed, which traditionally leads to high data fragmentation (dispersion) across physical disks. When it comes time to recover that data, the disk heads on an HDD would normally have to perform thousands of "seek" operations to find the scattered blocks, resulting in very slow recovery speeds.

Huawei solves this by calculating the data dispersion in real-time during the write process. The system intelligently rearranges and groups related data blocks together on the disk media. Because the data is stored in a physically optimized, sequential manner, the recovery process can utilizesequential readsrather than random reads. This allows OceanProtect to deliver recovery performance that is significantly higher than traditional backup appliances, ensuring that businesses can restore services rapidly after an outage or data loss event.