Design and Implementation of Mesh RAID with Multiple Parities 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 Mesh RAID that is 3 fault tolerant orthogonal RAID. And, we implemented Mesh RAID using VLSD. Mesh RAID is not tolerant of only disk fault but also tolerant of string fault. In addition, we also proposed Composite RAID, which is an easy implementation of complex RAID system by combining VLSD classes. We also implemented Composite RAID based Mesh RAID. In this paper, we propose Mesh RAID MP(Multiple Parities), which has multiple fault tolerance using multiple parities. Specifically, we design and implement MeshRAID2P. Furthermore, we employ RAID DP, which has row parity and diagonal parity, as 2FT RAID.