DEMOTING TRACKS FROM A FIRST CACHE TO A SECOND CACHE BY USING A STRIDE NUMBER ORDERING OF STRIDES IN THE SECOND CACHE TO CONSOLIDATE STRIDES IN THE SECOND CACHE

摘要

Information on strides configured in the second cache includes information indicating a number of valid tracks in the strides, wherein a stride has at least one of valid tracks and free tracks not including valid data. A determination is made of tracks to demote from the first cache. A first stride is formed including the determined tracks to demote. The tracks from the first stride are added to a second stride in the second cache that has no valid tracks. A target stride in the second cache is selected based on a stride most recently used to consolidate strides from at least two strides into one stride. Data from the valid tracks is copied from at least two source strides in the second cache to the target stride.

主权项

1. A method for managing data in a computer readable cache system comprising a first cache, a second cache, and a storage system comprised of storage devices, comprising:
maintaining information on strides configured in the second cache, including information indicating a number of valid tracks in the strides, wherein a stride has at least one of valid tracks and free tracks not including valid data, 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; forming a first stride including the determined tracks to demote; adding the tracks from the first stride to a second stride in the second cache that has no valid tracks; selecting a target stride in the second cache based on a stride most recently used to consolidate strides from at least two strides in the second cache into the target stride; and copying data from the valid tracks from the at least two strides in the second cache to the target stride.