The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Dec. 29, 1998

Filed:

May. 31, 1996
Applicant:
Inventors:

Clinton L Ballard, Suquamish, WA (US);

Timothy W Smith, Seattle, WA (US);

Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G06F / ;
U.S. Cl.
CPC ...
395825 ; 711-4 ;
Abstract

Disk I/O average access time is improved by estimating access time for pending I/O requests and selecting the request with the lowest estimated access time as the next request to be processed. To provide fast run-time estimation, disk characteristics are derived off-line and stored in files/tables for access during run-time estimation. A time (RT) to rotate the disk from a reference sector to each physical sector on the hard drive is derived and stored for each logical block address (LBA). A time (HT) for the heads to move an incremental number of cylinders also is derived. Access time of a destination LBA after completing access to a source LBA is estimated using estimated rotational times for the source and destination looked up in an RT table, and a head movement time estimate looked up in an HT table, based on a run-time calculated cylinder increment between the source and destination LBAs. Methods for developing rotational time estimates, head movement time estimates, disk zone characteristics, disk rotation time and other data are included.


Find Patent Forward Citations

Loading…