Abstract: In an example, there is disclosed a computing apparatus, having one or more logic elements, including at least one hardware logic element, comprising a network-aware data repair engine to compute a feasible repair log for n fragments of an original data structure, comprising: receiving a predictive failure scenario; identifying at least one repair ?i for the failure scenario; determining that ?i is feasible; and logging ?i to a feasible repair log. When a node failure occurs, a network cost may be computed for each repair in the feasible repair log, and an optimal repair may be selected.

Abstract: A controller device is configured to communicate with storage nodes of a distributed storage system (DSS) in which erasure codes are used to encode source data onto the storage nodes and ranks of matrices containing coding coefficients associated with the erasure codes indicate whether repairs of failed storage nodes of the DSS are feasible. A decomposition structure is generated to be used as a guide for transforming the matrices to upper triangle form (UTF) for use in computing the ranks of the matrices. While the DSS is operating to perform repairs of the failed storage nodes, as part of determining feasible repair strategies that will preserve subsequent repairs of failed storage nodes, the ranks of the matrices are computed by transforming the matrices to UTF using operations on the submatrices according to the decomposition structure.

Abstract: A controller device is configured to communicate with storage nodes of a distributed storage system (DSS) in which erasure codes are used to encode source data onto the storage nodes and ranks of matrices containing coding coefficients associated with the erasure codes indicate whether repairs of failed storage nodes of the DSS are feasible. A decomposition structure is generated to be used as a guide for transforming the matrices to upper triangle form (UTF) for use in computing the ranks of the matrices. While the DSS is operating to perform repairs of the failed storage nodes, as part of determining feasible repair strategies that will preserve subsequent repairs of failed storage nodes, the ranks of the matrices are computed by transforming the matrices to UTF using operations on the submatrices according to the decomposition structure.

Abstract: In an example, there is disclosed a computing apparatus, having one or more logic elements, including at least one hardware logic element, comprising a network-aware data repair engine to compute a feasible repair log for n fragments of an original data structure, comprising: receiving a predictive failure scenario; identifying at least one repair ?i for the failure scenario; determining that ?i is feasible; and logging ?i to a feasible repair log. When a node failure occurs, a network cost may be computed for each repair in the feasible repair log, and an optimal repair may be selected.