Browse Prior Art Database

Small Computer System Interface Device Driver Configuration Management Mechanism

IP.com Disclosure Number: IPCOM000108789D
Original Publication Date: 1992-Jun-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 2 page(s) / 65K

Publishing Venue

IBM

Related People

Sotomayor Jr, GG: AUTHOR

Abstract

This article describes a technique to keep configuration information of devices added to or removed from a small computer system interface (SCSI) bus.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 55% of the total text.

Small Computer System Interface Device Driver Configuration Management Mechanism

       This article describes a technique to keep configuration
information of devices added to or removed from a small computer
system interface (SCSI) bus.

      When a mapping is made from a linear number to a SCSI triple
(card number, physical unit number [PUN] and logical unit number
[LUN]), there exists the possibility of that mapping changing if the
new devices are added to the SCSI bus or if devices are removed from
the SCSI bus.  This results in the operating system (OS) and
ultimately the user from knowing how to address a particular device
from one boot time to the next.

      Some simple mechanisms can be used which get around part of the
problem of adding devices in that devices must be added to an
existing system in a particular order. However, this does not address
the problem of removing a device that previously existed.

      In the technique of this disclosure when the system is booted,
it checks the SCSI bus(es) to determine what devices are present.  It
then gets the configuration information. The current configuration is
checked against the stored configuration.  If there are
discrepancies, they are resolved in the following manner:
1.   If a device is no longer present, the entry in the configuration
is marked as not present but the entry is not deleted from the table.
The entry could have been marked that the device may sometimes be not
present an...