Functional-Repair-by-Transfer Regenerating Codes
In a distributed storage system, a data file is distributed to several storage nodes, such that the original file can be decoded from any subset of the storage nodes of size larger than or equal to a certain threshold. Upon the failure of a storage node, the authors would like to regenerate it with minimal amount of data transmissions from the surviving nodes to the new node. This performance metric is called the repair-bandwidth. Another performance metric is the disk Input/Output (I/O) cost, which measures the number of bits a storage node needs to read out from its memory in order to repair the failed node.