Content locality-based caching in a data storage system

Abstract

A data storage caching architecture supports using native local memory such as host-based RAM, and if available, Solid State Disk (SSD) memory for storing pre-cache delta-compression based delta, reference, and independent data by exploiting content locality, temporal locality, and spatial locality of data accesses to primary (e.g. disk-based) storage. The architecture makes excellent use of the physical properties of the different types of memory available (fast r/w RAM, low cost fast read SSD, etc) by applying algorithms to determine what types of data to store in each type of memory. Algorithms include similarity detection, delta compression, least popularly used cache management, conservative insertion and promotion cache replacement, and the like.

1 . A method of content locality-based caching, comprising:
 processing data that is associated with a data storage system with a processor to determine its content locality; and   caching a portion of the processed data based on its determined content locality.   
     
     
         2 . The method of  claim 1  wherein the data that is associated with the data storage system is pre-cache data. 
     
     
         3 . The method of  claim 1  wherein caching includes caching a first portion of the processed data in a Solid State Drive. 
     
     
         4 . The method of  claim 3  wherein the first portion of the processed data comprises reference blocks. 
     
     
         5 . The method of  claim 3  wherein the first portion of the processed data comprises delta blocks. 
     
     
         6 . The method of  claim 3  wherein the first portion of the processed data comprises independent blocks. 
     
     
         7 . The method of  claim 1  wherein caching includes caching a first portion of the processed data in a Random Access Memory. 
     
     
         8 . The method of  claim 7  wherein the first portion of the processed data comprises delta blocks. 
     
     
         9 . The method of  claim 7  wherein the first portion of the processed data comprises independent blocks. 
     
     
         10 . The method of  claim 1  wherein the caching includes caching a first portion of the processed data in a Hard Disk Drive (HDD). 
     
     
         11 . The method of  claim 10  wherein the first portion of the processed data comprises delta blocks. 
     
     
         12 . The method of  claim 10  wherein the first portion of the processed data comprises independent blocks.