Abstract-We consider the problem of recovering from a single node failure in a storage system based on an (n, k) MDS code. In such a scenario, a straightforward solution is to perform a complete decoding, even though the data to be recovered only amount to l /kth of the entire data. This paper presents techniques that can reduce the network traffic incurred. The techniques perform algebraic alignment so that the effective dimension of unwanted information is reduced. Suppose the first node fails. To repair the failed node, the conventional method downloads 4 blocks from other nodes and then solves for the missing blocks Al and A 2 . Now we show a way to achieve the recovery while downloading only 3 blocks over the network. As illustrated by Figure 1, we Similarly, if the second node fails, we can download 3 blocks over the network to recover it. What if a non-systematic node fails? We can perform a change of variables, as illustrated by Figure 2 . The resulting situation is analogous to Figure 1.
In REF , Wu and Dimakis showed techniques that can reduce the repair bandwidth in the case where there is only a single node failure.
Reducing repair traffic for erasure coding-based storage via interference alignment
2009 IEEE International Symposium on Information Theory
2009 IEEE International Symposium on Information Theory
Computer Science