CACHE ARRANGEMENT FOR IMPROVING RAID I/O OPERATIONS

• US 20080270704A1
• Filed: 04/30/2007
• Published: 10/30/2008
• Est. Priority Date: 04/30/2007
• Status: Abandoned Application

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: He, Dingshan, Kenchammana-Hosekote, Deepak R.
• Application Number:
  US11/741,826
• Publication Number:
  US 20080270704A1
• Time in Patent Office: Days
• US Class Current: 711/129
• CPC Class Codes: G06F 11/1076 Parity data used in redundant arrays of independent storages, e.g. in RAID systems
• CPC Class Codes: G06F 12/0813 with a network or matrix configuration
• CPC Class Codes: G06F 12/0871 Allocation or management of cache space
• CPC Class Codes: G06F 2211/1028 Distributed, i.e. distributed RAID systems with parity
• CPC Class Codes: G06F 2212/262 configured as RAID
• CPC Class Codes: G06F 2212/284 being distributed
• CPC Class Codes: H04L 67/56 Provisioning of proxy services store-and-forward switching systems in data switching networks H04L12/54
• CPC Class Codes: H04L 67/5682 Policies or rules for updating, deleting or replacing the stored data

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.

Claims

1-7. -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. -20. (canceled)