Patent ID: 8941935
Filing Date: 2015-01-27
Classification: G11B

Abstract:
1. A method of refreshing data in a magnetic storage system having random access memory and non-volatile memory, the non-volatile memory comprising a magnetic storage medium comprised of a plurality of data tracks that are coarsely partitioned, wherein each coarse partition is in turn finely partitioned, the method comprising: storing, in the random access memory, fine data update information that identifies, by coarse and fine partition locations, data written to the magnetic storage medium; updating, in the random access memory, a plurality of coarse-level damage count values based on the fine data update information, wherein each coarse-level damage count value represents estimated damage to one of the plurality of coarse partitions; updating a table of finer-granularity damage counts based on the fine data update information stored to the random access memory, wherein the table of finer-granularity damage counts stores multiple damage counts associated with each of the coarse partitions associated with the table; updating, in random access memory, the coarse-level damage count values associated with each of the plurality of coarse partitions based on updates made to the table of finer-granularity damage counts; and storing the table of finer-granularity damage counts to the non-volatile memory; and initializing a data refresh of one of the plurality of coarse partitions in response to the associated coarse-level damage count value exceeding a threshold.