可重組化之虛擬儲存裝置

Abstract

由於科技的發展，今可見各式各樣的儲存設備。此研究動機欲發展一種可動態組態調整的儲存設備，其可滿足用戶對於儲存設備在效能和可靠性上的要求。 我們提出一種由多個相同或不同的儲存設備組成虛擬儲存設備的設計，並且採用堆積資料結構，有效率的實做邏輯區塊位址動態重新映射的機制，以達到儲存效能的優化，進而提出延遲映射的演算法已減少不必要的資料搬移。 最後實驗的部分，我們以快閃計記憶和硬碟所組成的一個虛擬儲存裝置原型，在EXT2檔案系統上測試真實及隨機製造的工作負荷，來評估此設計的效能。

The recent development of storage technology has resulted in the rapidly growing of the storage capacity and the emerging of various new storage devices. This research is motivated by the needs of a dynamically configurable storage device that can fit the needs of users in performance and reliability. In particular, we propose the design of a virtual storage device that is composed of multiple heterogeneous or homogeneous storage devices. An efficient LBA mapping implementation is presented to map any given LBA to a proper location of a component storage device. We then propose a dynamic remapping mechanism with a heap-based data structure to manage the moving of data among component storage devices for performance optimization. A lazy swapping method is also proposed to reduce the mapping overheads. The capability of the proposed design is evaluated with a prototype virtual storage device with a flash-memory storage drive and a hard drive over Linux and an ex2 file system and realistic/randomly generated workloads.