Patent ID: 8832377
Filing Date: 2014-09-09
Classification: G06F

Abstract:
1. A method for managing data in a computer readable cache system comprising a first cache, a second cache, and a storage system, comprising: maintaining information on strides configured in the second cache and occupancy counts for the strides indicating an extent to which the strides are populated with valid tracks and invalid tracks, wherein a stride having no valid tracks is empty, wherein the strides comprise data strides populated with tracks of data, and wherein the tracks are maintained in the storage system; determining tracks to demote from the first cache, wherein the first cache comprises a dynamic random access memory (DRAM) and wherein the second cache comprises n solid state storage devices; forming a first stride including the determined tracks to demote; stripping the first stride of tracks from the first cache across the n solid state storage devices to form a second stride in the second cache having an occupancy count indicating the stride is empty, wherein the first cache stores tracks comprising modified or unmodified data and sequential or non-sequential data, and wherein tracks formed in strides in the first cache to promote to the second cache comprise unmodified non-sequential data; determining a target stride in the second cache based on the occupancy counts of the strides in the second cache; determining at least two source strides in the second cache having valid tracks based on the occupancy counts of the strides in the second cache; and populating the target stride with the valid tracks from the source strides.