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Browse Prior Art Database

Reassigned Space Reuse when Table Overflow Occurs

IP.com Disclosure Number: IPCOM000117085D
Original Publication Date: 1995-Dec-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Asano, H: AUTHOR [+4]

Abstract

Disclosed is an algorithm which minimizes the overflow of the table for sector reassignment on Hard Disk Drives. This algorithm utilizes the charact eristics that some of the grown defects disappear during operation.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Reassigned Space Reuse when Table Overflow Occurs

      Disclosed is an algorithm which minimizes the overflow of the
table for sector reassignment on Hard Disk Drives.  This algorithm
utilizes the charact eristics that some of the grown defects
disappear
during operation.

The algorithm of this method is as follows:
  1.  When there is no host access within L minutes, the drive starts
       to perform "Self Read Test" (Fig. 1).
  2.  In "Self Read Test", the drive checks all sectors which has
been
       reassigned in past.  In this test, the drive will apply
certain
       stress like ECC correction disable to detect a permanent
defect.
       The sectors which passes this test is re-used by restoring the
       data in spare sector into original sector and discarding the
       table entry from Reassign Table (Fig. 2).
  3.  When the drive detects a sector which should be reassigned, it
       checks if there is any room in the Reassign Table.  If it is
       already full, the drive performs "Self Read Test" and then
       performs the ordinary reassignment.