Seagate Technology Incorporated

Chwee Fern Ee

YongPeng Chng

Yong Peng Chng

WeiLoon Ng

Swee Kieong Choo

Wing Hung Chan

Chew Boon Toh

A method to improve drive read performance in a disc drive includes powering-up a disk drive, reading reassigned sectors data from a reassign spare pool, and storing the reassigned sectors data in a reassigned cache segment. This method also includes initiating a read request, detecting a reassigned sector within the read request, and determining whether the requested sector can be located in the reassignment cache. If the reassigned sectors are found in the cache, then the method includes transferring the reassigned sector data from the reassignment cache to the read buffer or directly to the requesting host computer. If the reassigned sectors are not found in the cache, then the method includes seeking to the reassignment spare pool to fetch as much reassigned sectors data as the reassignment cache can hold. In another embodiment, the reassigned sectors data stored in a reassignment cache segment is located in a buffer.

Caching data from a pool reassigned disk sectors

A disc drive typically contains at least one disc which is divided into sectors. The method of eliminating reassignments involves copying data stored at one sector (referred to as a moving sector) to another sector (referred to as a moving spare), and assigning the logical address associated with the moving sector to the moving spare. The elimination process is repeated until the reassignments are eliminated. Verification of the data copied is conducted to ensure data integrity. Furthermore, the elimination process is preferably executed only when the disc drive is in an idle mode. Records are kept and updated as the process is carried out so that the process can be continued even if interrupted.

Method to eliminate reassignments

Growing community of inventors

Singapore, Singapore

Chwee Fern Ee