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1994-07-07
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July 7, 1994
_ _ _
/ / (_)
_\ \ \
(_)_/_/ ASPI-WCE v1.0 -
Changes the WCE (Write Cache Enable) bit on the Mode Sense Caching
page 08h via the ASPI device driver.
Copyright 1994, Seagate Technology, Inc. All rights reserved.
Seagate Technology, Inc.
B-5 Technical Support
920 Disc Drive
Scotts Valley, CA 95066
===============================================================
Usage: ASPI-WCE [SCSI ID]
switches:
SCSI ID - A valid SCSI ID in the range 0 to 6
(no switches) - prompt for SCSI ID info
Do NOT run this utility until you completely understand its function.
This utility issues a SCSI Mode Select command to your SCSI drive and
makes a fundamental change to the way it operates. The Write Cache
Enable bit (WCE) controls how the completion status of a disk write is
reported. When WCE is ON, the drive reports status complete as soon as
the data is taken in to the drive's ram buffer. This results in very
high turn around times and serves to dramatically speed up system IO.
When WCE is OFF, the drive reports status complete after the data is
physically written to the media.
Whether WCE should be ON or OFF usually depends on the operating
system. For example, a single user desk top computer system would
enjoy the benefits of Write Cache Enable being ON. Multi-user and
multi-tasking operating systems, such as Netware and unix based,
operate more efficiently if the bit is set to OFF. This is because
the operating systems have elaborate schemes in place to protect data
integrity. When the disk reports that a write has been successfully
completed, the operating system moves on to the next tasks. If there
were a problem writing the data out to the media after the drive gave
a good status on the write (to the drive buffer because WCE was ON)
then the operating system may be unable to direct the recovery of the
data.
ASPI-WCE will report the current WCE setting and ask if you want to
make a change. If you select YES, it will then ask if you want the
drive to remember this change after RESET. Before using ASPI-WCE, be
sure to read the ASPI-ID documentation for further information about
ASPI device drivers, Mode Sense pages and SCSI commands.
ASPI-WCE is designed for the support of users with Seagate disc drives
and has been tested with Adaptec, Acculogic, Always, DPT and Ultrastor
SCSI host adapters with their associated ASPI device drivers. (These
represent the HA's we had laying around in Tech Support, other HA's
with ASPI drivers should also work.)
===============================================================
=====Rev=Hist===============
Written with Borland Pascal v6.0
Revision History:
7/94 v1.0 Initial Public release.
============================
LICENSE AGREEMENT AND WARRANTY DISCLAIMER
This is a legal agreement between you the purchaser and Seagate
Technology, Inc. By accessing ASPI-WCE, (the "Software"), you agree
to be bound by the terms of this agreement. If you do not agree, do
not access the software.
Seagate provides the accompanying object code of the Software and
nonexclusively licenses its use to you on the following terms and
conditions. The Software is Seagate's proprietary, copyrighted
product. Seagate grants you a limited access to use one copy of the
Software. You may not copy, distribute the Software for resale. You
may not reverse engineer, modify, rent, or lease the Software. In
addition, you may not disclose the information or data incorporated in
the Software to others, in any format.
You accept the Software "as is" without any warranty whatsoever.
Seagate does not warrant that the Software will meet your
requirements; that the Software is fit for any particular purpose or
that the use of the Software will be error free.
SEAGATE EXPRESSLY DISCLAIMS ALL WARRANTIES, WHETHER ORAL OR WRITTEN,
EXPRESSED OR IMPLIED, INCLUDING WITHOUT LIMITATION WARRANTIES OF
MERCHANTABILITY, OR FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
WILL SEAGATE BE LIABLE TO YOU, YOUR CUSTOMERS OR OTHER USERS IN ANY
WAY BASED ON USE OF THE SOFTWARE, INCLUDING WITHOUT LIMITATION FOR ANY
LOSS OF PROFITS, LOSS OF DATA OR USE OF THE SOFTWARE OR INDIRECT,
INCIDENTAL, CONSEQUENTIAL, SPECIAL, OR EXEMPLARY DAMAGES ARISING OUT
OF OR IN CONNECTION WITH THE USE OR INABILITY TO USE THE SOFTWARE.
(C) 1994 Seagate Technology, Inc.
End of License Agreement.
-=EOF: ASPI-WCE.DOC=-