中文摘要
雲端儲存必須滿足多使用者同時快速存取資料的需求，這對於雲端運算系統是很重要的。快閃記憶體相對於傳統的硬碟有存取更快和消耗功率更低的優勢，但也有在隨機存取時效能很低以及有限的壽命[1]等缺點。這項快閃記憶體磁碟陣列管理技術，就是提供一個快閃記憶體磁碟陣列，在不影響使用壽命和資料安全性的同時，又能提供高效能的存取。
快閃記憶體磁碟陣列管理技術是在一台包含快閃記憶體磁碟陣列的一般商用儲存伺服器上，建構一個系統軟體。現今用來集合一群SSD最直覺的技術，便是使用硬體或軟體的磁碟陣列（Redundant Array of Independent Disks, RAID）。現有RAID5常用於儲存系統，但並非專門為快閃記憶體設計，在隨機寫入的狀況，對效能有很大的傷害。本技術使用虛擬實體位址轉換的技術，將隨機位址轉換成連續位址，突破現有RAID5技術的效能與壽命瓶頸，在讀取寫入效能上提升10倍，達到透過網路每秒一百萬次輸出入的能力。本技術並透過跨磁碟間的平均耗損機制，延長磁碟陣列的壽命達2倍。除了最佳化底層儲存和上層網路之外，本技術還提供了虛擬磁碟管理功能，可提供快照、複製、和自動精簡配置等功能，而不會對效能有任何影響。在虛擬磁碟管理功能中還有服務品質保證的功能，透過合理分配整體的吞吐量，可保證每個虛擬磁碟的最小頻寬。為了增加儲存空間的利用率，本技術也包含了針對虛擬磁碟空間離線壓縮的功能，有效提升空間利用率達兩倍。
Abstract
Cloud storage is vital to the cloud computing system, as it requires satisfying multiple users for accessing the data at high throughput. Flash memory features the advantages of being faster and lower power-consumption as compared to conventional hard disk, but also has the issues of low performance for random access and lifespan. Software Orchestrated Flash Array Technology (SOFA) has constructed a flash memory disk array, providing high random access while not affecting the lifespan and the safety of the data.
SOFA is to build a system software, running on a commodity storage server with a flash memory disk array. Nowadays the intuitive approach to aggregate a bunch of disks is hardware or software RAID. Currently RAID5 is widely used in storage systems, but it’s not designed for flash memories, and the performance will be highly impacted at random writes. The technology adapts virtual to physical address re-mapping, transferring random addresses to sequential addresses, and breaks through the performance bottleneck of RAID5, getting 10 times the read / write performance to make 1 million IOPS through network. The technology also doubles the lifetime of disk array of RAID5 by Global Wear Leveling across disks. In addition to the optimization of storage and network levels, the technology provides Volume Manager, capable of taking snapshot, volume clone, and thin provisioning without performance impact. There is Quality of Service (QoS) function embedded in Volume Manager, which guarantees the minimum bandwidth of each volume by well-arranging the whole throughput. To increase the utilization of storage capacity, the technology also includes off-line compression for data volumes, which doubles the available capacity of the storage system.
關鍵詞(Key Words)
固態硬碟(Solid State Drive；SSD)
快閃記憶體陣列 (All-flash Array；AFA)
陣列磁碟 (Redundant Array of Independent Disks；RAID)
每秒輸出入次數 (Input Output Per Second；IOPS)
服務品質保證 (Quality of Service；QoS)
虛擬磁碟空間管理程式 (Volume Manager)
相關檔案: 快閃記憶體磁碟陣列管理技術(全文)
