Browse Prior Art Database

Reassign Back at Power On Reset for Performance Improvement

IP.com Disclosure Number: IPCOM000118920D
Original Publication Date: 1997-Sep-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 2 page(s) / 36K

Publishing Venue

IBM

Related People

Fukuhisa, R: AUTHOR [+4]

Abstract

Disclosed is a mechanism of recovery and cancellation of the reassigned data sectors in Hard Disk Drive (HDD). HDD firmware tests the original data sectors which have been reassigned or were the candidates of reassignment, and if the sector is reusable, to store data, then HDD firmware reassigns back to the original data sector. As a result, performance degradation by reassign will be avoided, and also, spare data sectors can be used for other reassign operations.

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Reassign Back at Power On Reset for Performance Improvement

      Disclosed is a mechanism of recovery and cancellation of the
reassigned data sectors in Hard Disk Drive (HDD).  HDD firmware tests
the original data sectors which have been reassigned or were the
candidates of reassignment, and if the sector is reusable, to store
data, then HDD firmware reassigns back to the original data sector.
As a result, performance degradation by reassign will be avoided, and
also, spare data sectors can be used for other reassign operations.

      HDD has a capability to reallocate the data sector when a media
error is detected and the user does not care about this mechanism.
This mechanism, called reassign, is widely utilized in HDD.  But to
read/write a reassigned sector, additional seek, head switch, and
latency delay are  needed.  Therefore, performance degradation is
unavoidable comparing to  non-reassigned read/write operations.  In
addition, limited space for spare sectors will cause no-spare error
when all spare sectors are used  up.

      The disclosed method provides a mechanism to resolve the above
problems.  At Power On Reset (POR) time and/or by explicit commands,
HDD firmware tests the original data sectors of reassign source that
was previously reported by the media error.  If the sector is
reusable to read/write, reassign back operation is carried out.  If
it succeeded,  the data is restored to the original data sector (not
in spare sector)  an...