Patent ID: 8549222
Filing Date: 2013-10-01
Classification: G06F

Abstract:
1. A storage system including a processor, comprising: a primary storage subsystem configured as a cache, wherein the cache includes a plurality of flash memory devices organized as one or more flash cache Redundant Array of Independent Disk (RAID) groups; a first data layout engine configured to implement one or more first data layout 6 techniques that improve data access performance of the primary storage subsystem by serving random data access operations directed to the cache; a secondary storage subsystem having disks organized as one or more disk RAID groups, wherein an array of data blocks on the disks organized as one or more disk RAID groups is characterized by row and column dimensions associated with a track depth on each disk and a disk RAID group width; a second data layout engine configured to implement one or more second data layout techniques that improve data access performance of the secondary storage subsystem by transposing the random data access operations into sequential access operations for storing selected data retrieved from the cache on the disks in accordance with a write allocation decision; and a policy engine configured to implement data type prioritization policies, based on information stored in metadata that describes the selected data to initiate eviction of the selected data retrieved from the cache to the one or more disk RAID groups based on a data type of the selected data having a higher priority than data types of other data on the cache.