Unlock instant, AI-driven research and patent intelligence for your innovation.

Method and device of data access operation for selecting queue in disc memory

A technology of access operation and data access, which is applied in the recording of information on the disk, alignment of tracks on the disk, information storage, etc., can solve the problems affecting the seek time and achieve the effect of accurate access time estimation

Inactive Publication Date: 2004-05-26
HITACHI GLOBAL STORAGE TECH NETHERLANDS BV
View PDF1 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

But other factors also affect seek time

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Method and device of data access operation for selecting queue in disc memory
  • Method and device of data access operation for selecting queue in disc memory
  • Method and device of data access operation for selecting queue in disc memory

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0029] Disk Drive Design Overview

[0030] Rotating rigid disk drives typically consist of one or more smooth, flat disks permanently attached to a common spindle or hub. When more than one disk is used, the disks are stacked on the spindle parallel to each other and spaced apart so that they do not touch each other. The disk and spindle are rotated in unison at a constant speed by a spindle motor.

[0031] Spindle motors are typically brushless DC motors with a multi-phase electromagnetic stator and a permanent magnet rotor. The different phases of the stator are sequentially driven by drive currents in order to turn the rotor.

[0032] Each disk consists of a solid disc-shaped base or base with a hole in its center for passing the spindle. The substrate is usually made of aluminum, although glass, ceramic, plastic or other materials can also be used. The substrate is coated with a thin layer of magnetizable material and also coated with a protective layer.

[0033] Data i...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

In accordance with one aspect of the present invention, a seek profile table used by a disk controller contains multiple profiles for seek operations, and is accessed by a separate index table containing, for each permutation of key parameters, an index to a corresponding profile. In operation, the estimated seek time for an enqueued data access operation is obtained by accessing the applicable index table entry, using the value of the index entry to determine the corresponding profile, and using the profile to estimate the access time. Preferably, a 'time-based relocation expected access time' algorithm is used, in which a nominal seek time is established, and profile table entries express a probability that an operation with a given latency above the nominal seek time will complete within the latency period.. The expected access time is the latency plus the product of this probability and the time cost of a miss, i.e., the time of a single disk revolution.

Description

[0001] Cross References to Related Applications [0002] This invention is related to the following commonly-owned co-pending U.S. patent applications, which are hereby incorporated by reference: [0003] US Patent Application Serial No. 10 / 215,403 entitled "Method and System for Efficiently Calculating and Storing Expected Access Time Information for DASD" filed by Hall on August 8, 2002. [0004] U.S. Patent Application Serial No. 09 / 638,253 entitled "Space-Efficient Expected Access Time Algorithm for Hard Disk Drive Command Queue Ordering" filed on August 14, 2000 by Espeseth et al. technical field [0005] The present invention relates to a spinning disk data storage device, and more particularly to an algorithm for selecting an execution order of a plurality of queued data access operations in a disk data storage device. Background technique [0006] The second half of the twentieth century saw the phenomenon known as the information revolution. Although the informati...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): G06F3/06G06F12/00G11B5/09G11B5/55G11B5/596G11B19/00G11B20/10G11B21/08
CPCG11B5/5547
Inventor 戴维·罗比森·霍尔
Owner HITACHI GLOBAL STORAGE TECH NETHERLANDS BV