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Selectable Migration for Exporting Optical Media

IP.com Disclosure Number: IPCOM000112688D
Original Publication Date: 1994-Jun-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 70K

Publishing Venue

IBM

Related People

Power, RR: AUTHOR [+3]

Abstract

This article describes optical-to-optical migration for the purposes of:

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Selectable Migration for Exporting Optical Media

      This article describes optical-to-optical migration for the
purposes of:

o   Exporting the required data on the least expensive optical
    cartridge(s) which will hold the data and are compatible with the
    receiving system.

o   Aggregating fragmented data over one or several disk surfaces to
    the cartridge(s) allocated for exporting.

      The user may wish to export data from an optical library for
several reasons.  This may include (a) lazy data sets or (b) a large
amount of data needed by a remote user and security/cost reasons
require use of an optical disk rather than use of telecommunications
to send the data.

      Optical cartridges now come in a matrix of media types and
capacities.  The media may either be write-once (WO) or
magneto-optical (MO).  Additionally, the media may be either
single-sided (SS), double-sided (DS), and single (1X) or double (2X)
capacity.

      Based on the amount of the data to be exported from the optical
library dataserver, merely exporting the cartridge currently holding
the data may not be suitable or cost effective.  Additionally, the
data may be spread over multiple cartridges, as may be the case for
optical libraries emulating DASD.

      Our algorithm makes a completely automatic selection of media
cartridges for exporting data.  The user would earmark files to be
exported from a tree.  This tree could be on DASD, as it is on
hierarchical DASD-Optical storage systems.  Alternately, one would
load the optical cartridges to ascertain file sizes and build an
export tree.  Files to be exported could be denoted with the letter E
and the following suffixes.

E  or ES    Export to the same type (MO/WO) already being stored on

EW          Mandatory Export to Write-Once media

ER          Mandatory Export to Rewritable media

      The control uni...