Software RAID for Data Intensive Applications in Cloud Computing

Abstract

In this paper, we propose a software RAID to support data intensive applications in cloud computing. The proposed software RAID is based on DDR-SSD to enhance the performance of existing RAID systems. Also, we take the characteristics of DDR-SSD into account to design our software RAID. RAID level 5 which is generally used in data intensive applications has small write problems. In RAID level 5, to process a small write request, we need to read its parity block stored in disk, read old block, perform XOR operation, and write updated block and parity block. In this paper, we propose a differential-logging method which carefully considers the DDR-SSD to solve the small write problem in RAID level 5. We show that our proposed method out performs the existing software RAID through simulations.