Browse Prior Art Database

Automated SCSI I/O Adjustment

IP.com Disclosure Number: IPCOM000013653D
Original Publication Date: 2000-Aug-01
Included in the Prior Art Database: 2003-Jun-18
Document File: 1 page(s) / 26K

Publishing Venue

IBM

Abstract

Disclosed is a method to adjust the SCSI I/O characteristics for HDD(Hard Disk Drive).

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 100% of the total text.

Page 1 of 1

Automated SCSI I/O Adjustment

   Disclosed is a method to adjust the SCSI I/O characteristics for
HDD(Hard Disk Drive).

      The SCSI I/Os will be degraded with heavy loaded environment.
(long cables, multiple
drives, backplane, connector etc.) This degradation may
cause an error during a data
transfer. If a HDD could diagnose the waveform and adjust
the own characteristics,
the system would have a high reliability.

This method can realize that by using the following functions.
1. adjustable SCSI I/O
2. diagnosis the waveform
3. initiator mode
4. unique commands to request a diagnosis and adjustment

     Here is a sequence of this method. Fig-1 is an example of
system to describe the
sequence.

Host -----*------------------*

    | |
HDD 1 HDD 2

Fig-1. an example of system

1. After powering on, HDD 2 become an initiator.
2. HDD 2 issue the diagnosis request command to HDD 1.
3. HDD 2 assert the SCSI signals and HDD 1 receive this signal
to check the
waveform.
4. HDD 1 return the result of diagnosis to HDD 2.
5. HDD 2 adjust the characteristics and assert it again.
6. HDD 1 check the waveform again.
7. repeat Step 4 to Step 6 until HDD 1 get the most
appropriate setting.

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