RAID 2.0+ divides each disk into fixed-size chunks, typically 8 MB, and chunks from different disks are combined into chunk groups according to the configured RAID policy. During LUN creation, these chunk groups are further divided into grains, which are then mapped to LUNs to enable fine-grained allocation and efficient management of storage resources.

Small I/O writes such as 500 KB are handled through the write cache mechanism, where data is first written to memory and WAL cache to ensure performance and reliability. Direct write to HDD is typically for large I/O, not small I/O.

SNMPv2c uses community strings rather than USM users, so configuring a USM user is not required. SNMPv3 relies on USM users for authentication and security, not community strings, making the statement incorrect.

Subhealth management in Huawei OceanStor Pacific series provides fine-grained health detection and management for key system components, including processors, disks, networks, and processes, enabling early fault identification and proactive risk handling before failures escalate.

SmartKit
Explanation:
SmartKit serves as the desktop management platform for Huawei OceanStor Dorado series, integrating various O&M tools into a unified interface and providing guided, standardized operations for mainstream O&M scenarios.