Cache arrangement for improving raid i/o operations

Abstract

The embodiments of the invention provide a method, apparatus, etc. for a cache arrangement for improving RAID I/O operations. More specifically, a method begins by partitioning a data object into a plurality of data blocks and creating one or more parity data blocks from the data object. Next, the data blocks and the parity data blocks are stored within storage nodes. Following this, the method caches data blocks within a partitioned cache, wherein the partitioned cache includes a plurality of cache partitions. The cache partitions are located within the storage nodes, wherein each cache partition is smaller than the data object. Moreover, the caching within the partitioned cache only caches data blocks in parity storage nodes, wherein the parity storage nodes comprise a parity storage field. Thus, caching within the partitioned cache avoids caching data blocks within storage nodes lacking the parity storage field.

1 - 7 . (canceled) 
   
   
       7 . A method for cache management within a distributed data storage system, said method comprising:
 partitioning a data object into a plurality of data blocks;   creating at least one parity data block from said data object;   storing said data blocks and said parity data block within storage nodes;   caching said data blocks within a partitioned cache, wherein said partitioned cache comprises a plurality of cache partitions, wherein said cache partitions are located within said storage nodes,   wherein said caching within said partitioned cache only caches said data blocks in parity storage nodes, wherein said parity storage nodes comprise a parity storage field;   updating said data object, said updating comprising
 annotating a write request with information regarding changed data blocks within said data object, and 
 sending said write request only to said parity storage nodes; and 
   reading said data blocks and said parity data block from said storage nodes;   wherein said caching within said partitioned cache comprises avoiding caching said data blocks within storage nodes lacking said parity storage field,   wherein said sending of said write request only to said parity storage nodes comprises simultaneously performing an invalidation operation and a write operation, and   wherein said caching of said data blocks within said partitioned cache comprises, when said storage nodes comprise more than one of said parity storage nodes, caching said data blocks in any of said parity storage nodes.   
   
   
       8 - 20 . (canceled)