開放通道固態硬碟(Open-Channel Solid-State Drive, OCSSD)被視為可以解決目前固態硬碟效能瓶頸的架構之一，其機制在於將部分快閃記憶體轉譯層功能轉移至主機端以減輕固態硬碟控制器負擔。由OCSSD之概念所衍生的分區命名空間固態硬碟(Zoned Namespace Solid-State Drive, ZNS SSD)透過將邏輯空間劃分成不同的分區(Zone)，並限制分區的操作必須循序寫入，因此可大幅降低垃圾收集的執行頻率，降低寫入放大的影響，以及延長固態硬碟壽命。
強制要求循序寫入可能會限制ZNS SSD的效能，因此本研究提出一個緩衝架構，將資料緩衝在主機記憶體中，待分區狀態轉換時再將資料依序寫回，提升ZNS SSD的吞吐量，若欲更新資料已緩衝在記憶體裡，則可以直接更新該筆資料，藉此減少NAND快閃記憶體擦除的次數。
本研究透過QEMU (Quick Emulator)模擬一個ZNS SSD進行實驗，在連續讀寫的測試結果中，本研究之架構在最佳情況下讀取和寫入的效能分別為SPDK的1448.47%和2312.85%，而在最差情況下，讀取和寫入的效能分別下降至SPDK的90.06%和88.16%，在讀寫次數的測試結果中，本研究之架構相較於SPDK減少了23.44%的讀寫請求次數，因此可以證實本研究所提出之I/O緩衝方法的效益。

Open-Channel Solid-State Drive (OCSSD) is regarded as one of the architectural solutions capable of mitigating the current performance bottlenecks in solid-state drives. Its mechanism involves the transfer of certain functions of the Flash Translation Layer (FTL) from the solid-state drive controller to the host, thus alleviating the workload of the solid-state drive controller. Zoned Namespace Solid-State Drives (ZNS SSDs), deriving from the OCSSD concept, partition the logical space into discrete zones and impose a sequential write requirement within each zone. This strategy significantly reduces the frequency of garbage collection, thus extending the lifespan of the solid-state drive.
The enforced requirement of sequential writes imposes limitations on the performance of ZNS SSDs. Therefore, the research proposed an approach to buffering I/O data in the host memory for ZNS SSDs. The data is temporarily cached in the host memory until a zone state transition occurs, at which point the data is sequentially written back. This innovative strategy aims to enhance the throughput of ZNS SSDs. Additionally, for cases requiring data updates, if the relevant data is already buffered in memory, direct updates can be performed, effectively reducing the frequency of NAND flash memory erasures.
Simulations on sequential write and read have been performed on a simulated ZNS SSD using QEMU (Quick Emulator). The results show that the approach proposed in this research achieved read and write performance improvements of 1448.47% and 2312.85%, respectively, compared to SPDK under the best conditions. The approach proposed in this research also demonstrated a reduction of 23.44% in read and write requests compared to SPDK. Therefore, it can be confirmed that the approach to buffering I/O that introduced in this research offers significant benefits.

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