Patent ID: 7958310
Filing Date: 2011-06-07
Classification: G06F

Abstract:
1. A computer program product comprising a computer readable program stored on a tangible storage device, wherein the computer readable program when executed on a computer causes the computer to: receive write data at a cache; destage the write data sequentially to a coarse grained repository and destage a directory entry for the write data to a coarse grained directory for each write in response to a first write of first write data satisfying a repository policy and until the repository policy is not satisfied for a specified number of writes of subsequent data after the first write, wherein the coarse grained repository does not store a previous instance of the write data; and destage the write data to a fine grained repository overwriting an existing instance of the write data and destage the directory entry to a fine grained directory if the write data does not satisfy the repository policy for at least one of the first write and the specified number of writes subsequent to the first write, wherein the fine grained repository stores a previous instance of the write data.