高階固態硬碟架構下的通道管理方法

Abstract

隨著快閃記憶體的快速發展，類似固態硬碟(SSD)這樣子輕巧、耐震且儲存密度高的裝置越來越普遍。而這類的裝置內部會使用像RAID一樣的平行架構，其目的是藉由並排存取快閃記憶體的通道來提升單位時間的存取速度。傳統上這些通道的管理方式是以同步運作的方式來處理，然而因為快閃記憶體具有與一般儲存裝置截然不同的特性，在面對小資料隨機寫入的情況下無法發揮多通道應該有的效能，因此這些通道需要一套有效的管理方法來提升存取的平行度，使小資料隨機寫入的效能可以提高。本篇論文提出三項多通道的管理機制，解決多通道在過去所面臨的多項管理瓶頸。實驗結果發現，與傳統的管理方法比較，我們的方法在8個通道及2.5% overprovision的情況下，小資料隨機寫入的效能為同步運作通道的3.72倍。

With the rapid development of flash memory, the devices, similar to solid-state disks, are compliant to small form-factor but offer very high storage density. Advanced SSDs employ parallel architectures, performing like small RAIDs. The purpose is to enhance the throughput of access by side by side these channels. Traditionally, the management of these channels is the way to deal with synchronization. However, because the flash memory storage devices in general have different characteristics, synchronized channels cannot exploit the behavior of multi-channels against to the small and random write requests. Smart management of channels helps to improve parallelism of read and write. This paper proposed 3 mechanisms of channel management to improve the performance of multi-channel against to the small random write. Experimental results show that our channel management scheme, in small random write, can be 3.72 times of IOPs improvement over synchronized channels under 8 channels and 2.5% overprovision.