A Robust Fault-Tolerant and Scalable Cluster-wide Deduplication for Shared-Nothing Storage Systems

Deduplication has been largely employed in distributed storage systems to improve space efficiency. Traditional deduplication research ignores the design specifications of shared-nothing distributed storage systems such as no central metadata bottleneck, scalability, and storage rebalancing. Further, deduplication introduces transactional changes, which are prone to errors in the event of a system failure, resulting in inconsistencies in data and deduplication metadata. In this paper, we propose a robust, fault-tolerant and scalable cluster-wide deduplication that can eliminate duplicate copies across the cluster. We design a distributed deduplication metadata shard which guarantees performance scalability while preserving the design constraints of shared- nothing storage systems. The placement of chunks and deduplication metadata is made cluster-wide based on the content fingerprint of chunks. To ensure transactional consistency and garbage identification, we employ a flag-based asynchronous consistency mechanism. We implement the proposed deduplication on Ceph. The evaluation shows high disk-space savings with minimal performance degradation as well as high robustness in the event of sudden server failure.Comment: 6 Pages including reference

Data Deduplication Technology for Cloud Storage

With the explosive growth of information data, the data storage system has stepped into the cloud storage era. Although the core of the cloud storage system is distributed file system in solving the problem of mass data storage, a large number of duplicate data exist in all storage system. File systems are designed to control how files are stored and retrieved. Fewer studies focus on the cloud file system deduplication technologies at the application level, especially for the Hadoop distributed file system. In this paper, we design a file deduplication framework on Hadoop distributed file system for cloud application developer. Proposed RFD-HDFS and FD-HDFS two data deduplication solutions process data deduplication online, which improves storage space utilisation and reduces the redundancy. In the end of the paper, we test the disk utilisation and the file upload performance on RFD-HDFS and FD-HDFS, and compare HDFS with the disk utilisation of two system frameworks. The results show that the two-system framework not only implements data deduplication function but also effectively reduces the disk utilisation of duplicate files. So, the proposed framework can indeed reduce the storage space by eliminating redundant HDFS file