Browse Prior Art Database

Methods of Reporting of Skipped Error Locations

IP.com Disclosure Number: IPCOM000123045D
Original Publication Date: 1998-Apr-01
Included in the Prior Art Database: 2005-Apr-04
Document File: 3 page(s) / 68K

Publishing Venue

IBM

Related People

Hashimoto, M: AUTHOR [+4]

Abstract

Disclosed are methods to report information of skipped error locations by the storage devices such as hard disk drive. In a real time data processing environment such as audio visual data processing, it is required for storage devices to return the requested data in the certain period of time. In case of Small Computer System Interface (SCSI), an operation mode for storage devices is already defined for this kind of environment as "Read Continuous" mode. In "Read Continuous" mode, a storage device may skip error recovery operation and may return data which contain error. However, by this "Read Continuous" mode operation, the host system can not know which sector contains data include errors.

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Methods of Reporting of Skipped Error Locations

      Disclosed are methods to report information of skipped error
locations by the storage devices such as hard disk drive.  In a real
time data processing environment such as audio visual data
processing, it is required for storage devices to return the
requested data in the  certain period of time.  In case of Small
Computer System Interface (SCSI), an operation mode for storage
devices is already defined for this  kind of environment as "Read
Continuous" mode.  In "Read Continuous" mode, a storage device may
skip error recovery operation and may return  data which contain
error.  However, by this "Read Continuous" mode operation, the host
system can not know which sector contains data include errors.  The
host system may perform its own data recovery if it  has information
about error locations when it has redundancy such as disk  array
configuration.

      Fig.1 shows internal operation to record the skipped error
locations.

      The following three methods are defined to report skipped error
locations,
  1.  The storage device adds an attribute to each sector which
       indicates the data in the sector include error(s), during
       the data transfer to the host system from the storage device.
        (Fig.2 shows the example of this type of the operation.)
  2.  The storage device transfers  error location information
       following the requested data transfer....