Design and implementation of 3D MeshRAID in Virtual Large-Scale Disks

Abstract

Recently, the demand of low cost large scale storages increases. We developed VLSD (Virtual Large Scale Disks) toolkit for constructing virtual disk based distributed storages, which aggregate free spaces of individual disks. However, in order to construct large-scale storage, more than or equal to 3 fault tolerant RAID is important. In the previous work we proposed MeshRAID that is 3 fault tolerant orthogonal RAID. And, we implemented MeshRAID using VLSD. MeshRAID is a hierarchical RAID that shares elemental disks. The structure of hierarchical RAID is tree but the structure of MeshRAID is DAG(Directed Acyclic Graph). MeshRAID is not tolerant of only disk fault but also tolerant of string fault. Furthermore, in hierarchical RAID, the larger the number of layers is, the higher the reliability of the system. In MeshRAID, increasing the layers is equivalent to increasing the dimensions. In this paper, we implement 3 dimensional MeshRAID and evaluate it. © 2011 IEEE.