Patent ID: 8825944

Claim:
A computer program product for managing data in a cache system comprising a first cache, a second cache, and a storage system comprised of storage devices, the computer program product comprising a non-transitory computer readable storage medium having computer readable program code embodied therein that executes to perform operations, the operations comprising: maintaining in the first cache modified and unmodified tracks from the storage system subject to Input/Output (I/O) requests; determining to demote tracks from the first cache; determining whether there are enough tracks ready to demote to form a stride, wherein tracks are written to the second cache in strides defined for a Redundant Array of Independent Disk (RAID) configuration; populating a stride with tracks ready to demote in response to determining that there are enough tracks ready to demote to form the stride; promoting the stride of tracks to demote from the first cache to the second cache; demoting from the first cache the stride of tracks promoted to the second cache; and destaging the tracks in the second cache that are modified to the storage system.