Browse Prior Art Database

Automated Library Control Attachment

IP.com Disclosure Number: IPCOM000109817D
Original Publication Date: 1992-Sep-01
Included in the Prior Art Database: 2005-Mar-24
Document File: 3 page(s) / 117K

Publishing Venue

IBM

Related People

Peake, JW: AUTHOR

Abstract

This article describes a new attachment method for the control of automated libraries that eliminates the requirement for separate interfaces for both the control of the library and the reading and writing of data on the media managed by the library.

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

Automated Library Control Attachment

       This article describes a new attachment method for the
control of automated libraries that eliminates the requirement for
separate interfaces for both the control of the library and the
reading and writing of data on the media managed by the library.

      Tape, and more recently optical media, has been a key element
of data storage because of its nature as a removable media.
Removable media enables great quantities of data to be stored without
the high cost of online disk storage.  A large number of tapes and a
relatively small number of tape devices can provide highly cost
effective storage for data that does not require the fast access
capabilities  of online disk storage.

      Historically, human operators have been involved in mounting
and dismounting the tapes on tape devices.  Recently, automated
library systems are replacing human operators.  These systems treat
the library automation mechanism and control as a separate entity
from the read/write devices associated with the library.  In so
doing, they require more hardware in terms of channels, cables, etc.,
and require a complex host software to coordinate the actions of the
library with the read/write devices.

      The attachment method described herein has key advantages over
other approaches in the following areas:
*  Connectivity--This means the ability of the hosts attached to the
library to control and have access to the data stored on the volumes
contained in an automated library through multiple paths.
*  Installation--Installation here means the cabling attachment of a
library to host systems.
*  Cost--Cost in terms of installation costs for cables, additional
channels, etc.
The Attachment Method

      The attachment method combines the flow of library control AND
device control and data over the same host connection, thereby
eliminating the need for a separate connection between the host and
the library controller.  Key to making this practical is that the
purpose of an automated library is to mount and dismount media on a
specific device in the library.  This means that by sending a LIBRARY
command to the specific device address that needs to be
mounted/dismounted, the control of the library can be easily
"piggy-backed" on each device address.

      This accomplishes three purposes:
      1.  No additional host channels or cables are required.
      2.  It simplifies the host software because it does not have to
keep track of a separate address for the device and the automation
system that mounts/dismounts media on the device.
      3.  Since the library command is sent on the specific device
address that needs servicing, no parameters are needed to specify
which dev...