Browse Prior Art Database

Adaptive Seek profile for Rotational Position Optimization

IP.com Disclosure Number: IPCOM000013634D
Original Publication Date: 2000-Jul-01
Included in the Prior Art Database: 2003-Jun-18
Document File: 1 page(s) / 28K

Publishing Venue

IBM

Abstract

Disclosed is a technique to estimate a time effectively for seek operation which is used for Rotation Positional Position Optimization(RPO) under queued random operation . There is one method that is based on a table which indicates the relation between a seek length and a time to complete the operation. But the relation varies from Hard Disk Drive(HDD) to HDD and from an environment to an environment. This means that there is a possibility of performance loss due to inaccurate seek time estimation when the table does not match to the environment or the drive. Inaccurate seek time estimation may cause a misrevolution. Then, this method results in a big variance in performance from HDD to HDD and from an environment to an environment. To make the estimation accurate, adjust the table based on the estimated seek time and the actual seek time. Other feature is that the table is save on a media periodically. It enables to get a maximum performance even after Power On Reset. For RPO operation, seek time is expected on a table as follow. example of seek profile table. Servo IDs Max. seek length

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 62% of the total text.

Page 1 of 1

Adaptive Seek profile for Rotational Position Optimization

Disclosed is a technique to estimate a time effectively for seek operation which is used for
Rotation Positional Position Optimization(RPO) under queued random operation . There is one
method that is based on a table which indicates the relation between a seek length and a time to
complete the operation. But the relation varies from Hard Disk Drive(HDD) to HDD and from an
environment to an environment. This means that there is a possibility of performance loss due
to inaccurate seek time estimation when the table does not match to the environment or the
drive. Inaccurate seek time estimation may cause a misrevolution. Then, this method results
in a big variance in performance from HDD to HDD and from an environment to an environment. To
make the estimation accurate, adjust the table based on the estimated seek time and the actual
seek time. Other feature is that the table is save on a media periodically. It enables to get a
maximum performance even after Power On Reset.

For RPO operation, seek time is expected on a table as follow.

example of seek profile table.

Servo IDs | Max. seek length
--------+---------------------

10 | 14
11 | 18
12 | 25
13 | 30

For example to seek 20 cylinder, 11 Servo IDs is enough time to complete a seek operation upto
18 cylinder. 12 servo IDs is enough to complete a seek operation upto 25 cylinder. Then, 20
cylinder seek time is expected as 12 servo IDs.

In this invention, an estimated seek t...