Method of, and apparatus for, accelerated data recovery in a storage system

摘要

There is provided a method of defining a layout mapping function for a parity distributed RAID array comprising a plurality of target objects, the layout mapping function defining the mapping of the group-address space to the target-address space in the array and comprising a matrix defining a unit space across a plurality of target objects, the matrix comprises columns defining said target objects and rows defining sequential units on said target objects, the method comprising: a) defining a layout of stripe groups across the target objects by defining a pattern comprising a plurality of stripe groups into a predetermined pattern and repeating said pattern across said matrix, each stripe group comprising a plurality of data units and a plurality of parity units; and b) implementing said layout on said target objects of said RAID array. By providing such a method, the data access pattern for reconstruction is less scattered than known arrangements, such that disk read ahead potential can be improved with respect to repair and rebuild.