MuLe-RAID:面向大容量高性能SSD的层次化RAID

利用RAID机制构建基于闪存的SSD可以提高SSD的性能和可靠性,但是随着SSD容量的增大,传统的单层RAID结构容易造成控制器的瓶颈.针对这个问题,提出了一种新的RAID策略——MuLe-RAID(Multiple Level RAID),给出了详细架构和设计细节.其采用层次化RAID结构,设置多个控制器,在每一层的控制器中实现不同粒度的损耗均衡管理,在保证SSD损耗均衡的同时,通过减轻控制器的瓶颈提高了SSD的性能.为了提高可靠性,MuLe-RAID采用了冗余机制,能够达到RAID5的容错级别.通过模拟实验测试表明,在大容量SSD中,相比传统RAID,MuLe-RAID在保证损耗均衡的基础上有大约30%的性能提升.

MuLe-RAID: Constructing Large Scale and High-Performance SSD with Multiple Level RAID Architecture

RAID mechanism can be used to construct SSD (solid state disk) based on flash chips to enhance its performance and reliability. With SSDs capacity increasing, in single level RAID structure, controller is apt to become the performance bottleneck of the SSD. To deal with this problem, this paper proposes a novel RAID strategy: Multiple level RAID (abbreviated as MuLe-RAID) and describes its design in detail. It adopts multiple levels RAID architecture, set several controllers in which different grains wear leveling mechanisms are implemented. Meaning while, it has redundancy strategy which can approach the same fault tolerating effect with RAID5. Based on simulator, we measure the performance and wear leveling of MuLe-RAID. It shows that, compared with traditional RAID, MuLe-RAID can guarantee the good wear leveling and boost up the performance by 30% approximately.