Patent Number: 6,298,415

Title: Method and system for minimizing writes and reducing parity updates in a raid system

Abstract: A method and system for updating stored data with received data in a cache associated with the data storage system is provided, where the data storage system comprises N data storage drives, where data and calculated parity are striped across N data storage drives, where a stripe comprises multiple data sectors on each of N data storage drives. An associated cache is provided with the data storage system into which data is received. The data in the cache is periodically examined to determine if the cache includes all sequential data sectors contained within a complete stripe within the data storage system. Parity is calculated for the complete stripe by first calculating a range of sectors between which all sectors received into the cache for the complete stripe fall. Next, only those sectors within the range of sectors which are not included in the data in the cache for the complete stripe are read from the N data storage drives into the cache. Finally, the range of sectors in the cache for the complete stripe are logically combined. The parity is calculated such that input/output operations within said data storage system are minimized.

Inventors: Riedle; Linda Ann (Apex, NC)

Assignee: International Business Machines Corporation

International Classification: G06F 11/10 (20060101); G06F 011/10 ()

Expiration Date: 10/02/2018