Browse Prior Art Database

Control of Attachable Devices in a Distributed Computer Environment

IP.com Disclosure Number: IPCOM000103853D
Original Publication Date: 1993-Feb-01
Included in the Prior Art Database: 2005-Mar-18
Document File: 2 page(s) / 89K

Publishing Venue

IBM

Related People

Ford, G: AUTHOR [+2]

Abstract

In a computer environment containing multiple computer systems, connected by a communications network, (where each system is known as a 'node'), it is often the case that a user of one of the several systems wishes to acquire temporary, exclusive access to a device or set of devices, without modifications to the system, human intervention, and without interfering with the access rights of other users for different devices. It is also the case that a system should provide for modifiable ownership of of such devices.

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

Control of Attachable Devices in a Distributed Computer Environment

      In a computer environment containing multiple computer systems,
connected by a communications network, (where each system is known as
a 'node'), it is often the case that a user of one of the several
systems wishes to acquire temporary, exclusive access to a device or
set of devices, without modifications to the system, human
intervention, and without interfering with the access rights of other
users for different devices.  It is also the case that a system
should provide for modifiable ownership of of such devices.

      This disclosure describes a method for accomplishing the
foregoing objectives by use of a set of computer programs (called
servers).  In this disclosure, there will be a server, called the
host server (or host) that maintains a complete set of information
regarding all devices to be controlled, and a set of servers, called
remote servers (or remotes) which operate in conjunction with the
host to accomplish these operations.

      The following discussion describes a common program for
controlling (managing) a collection of devices.  A copy of this
program must exist on each node in the collection of nodes
participating in the management of devices by this process.  A
variable is set that informs the program whether it is to operate in
either a HOST or REMOTE mode.

      The HOST copy has a file that contains a description of all
devices to be controlled.  This is called the Device Data file.  This
file contains such information as:  device type, features, system
affinity (see Figure) and an affinity name.  The affinity name allows
a user to easily specify a list of devices on which a volume may be
mounted.  There are also flags to indicate special device
capabilities.  The host then builds a list of active devices, which
are available for use.

      A user, who wishes to access a mountable volume, sends a
message to the version of the program running on his/her own node
specifying the requested volume identity.  The program accesses a
catalog of such volumes to verify the ownership.  When the catalog
entry for this volume is located, the entry is examined for any
device affinity or a specific device type.

      If either is found, the Device Data file is referenced to
determine what physical devices meet the specified criteria.  When a
device is found, a message is sent...