A Flexible Framework to Enhance RAID-6 Scalability via Exploiting the Similarities among MDS Codes

With increasing demand in high performance and reliability, RAID systems especially RAID-6 are widely used in data centers with the support of erasure codes. Among many RAID-6 implementations, one set of codes called Maximum Distance Separable (MDS) codes, aim to offer data protection against disk failures with optimal storage efficiency. Since today´s large data centers typically shift to the services of cloud computing, a challenging issue is how to accelerate the scaling process of RAID-6 systems based on MDS codes. To address this challenge, we propose a novel MDS Code Scaling Framework (MDS-Frame), which is a unified management scheme on various MDS codes to achieve high scalability. It bridges various MDS codes for flexible scaling via several intermediate codes. In our mathematical analysis, compared to typical RAID scaling approaches, MDS-Frame shows its advantages in the following aspects: It reduces more than 44.1% migration I/Os, saves the migration time by up to 95.2%, and speeds up the migration process by a factor of up to 20.7.