Deterministic Regenerating Codes for Distributed Storage

It is well known that erasure coding can be used in storage systems to efficiently store data while protecting against failures. Conventionally, the design of erasure codes has focused on the tradeoff between redundancy and reliability; under this criterion, an Maximum Distance Separable (MDS) code is optimal. However, practical storage systems call for additional considerations. In particular, the codes must be properly maintained to recover from node failures. Previous work by Dimakis et al. studied the problem of properly maintaining erasure codes to reduce the incurred network bandwidth, established fundamental bounds on the minimum repair bandwidth for maintaining MDS codes, and showed that the repair bandwidth can be reduced further at the cost of higher storage. In this paper we present techniques for constructing codes that achieve the optimal tradeoffs between storage efficiency and repair bandwidth.