Browse Prior Art Database

Method to Prevent Latent Errors in Automated Tape Libraries with Mirroring

IP.com Disclosure Number: IPCOM000118120D
Original Publication Date: 1996-Sep-01
Included in the Prior Art Database: 2005-Apr-01
Document File: 2 page(s) / 53K

Publishing Venue

IBM

Related People

Weber, HJ: AUTHOR

Abstract

Disclosed is a method to prevent latent errors in the symmetry of an automated tape library which utilizes tape mirroring from impacting operations.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 56% of the total text.

Method to Prevent Latent Errors in Automated Tape Libraries with
Mirroring

      Disclosed is a method to prevent latent errors in the symmetry
of an automated tape library which utilizes tape mirroring from
impacting operations.

      Tape libraries for mid-range and low-end computer systems are
relatively new.  Mirrored operations in such libraries involve the
reading and writing of two identical tapes simultaneously, where the
second copy may be used for off-site vaulting or for higher
reliability.

      In order to maintain the data integrity of such mirrored tapes,
any logical differences (in data recorded, etc.) of the tape pair
must be identified as an error.  Because many tapes (ten or more) can
be present  in a library when it is put into operation, such
differences may be present and represent errors that would only be
detected when tape operations (such as reading or writing) take place
on the tape pair. It  is possible that many hours, or even days or
weeks will go by before a  particular pair of mirrored tapes is
actually placed into tape drives and into use, thereby facilitating
the detection of this error.

      It is also likely that the computer operator responsible for
the tapes is not present, impacting the ability for continued
operations.

      The following method (or operation) can be performed by the
tape library when tapes are originally inserted.  It ensures that the
tape pairs are essentially free from such difference...