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From: cmaae30@uk.ac.ic.cc (Thomas Sippel - Dau)
Newsgroups: comp.unix.aix
Subject: Non-IBM 8mm Exabyte on RS/6000???
Message-ID: <1990Sep12.192939.5099@cc.ic.ac.uk>
Date: 11 Sep 90 23:00:00 GMT
Sender: news@cc.ic.ac.uk (USENET News System)
Organization: Imperial College Computer Center, London, UK
Lines: 41

In <1990Aug28.175456.24603@cimage.com> Brian Kelly writes:
> Has anyone tried to plug a non-IBM supplied Exabyte into an RS/6000?
> Should this work?   Is there anything special about IBM's Exabytes? 

I did, and found the following:

On startup the RISC/6000 checks at each scsi address what devices are 
available, and when it finds one, it sends an enquiry command to find out
what it is. Good scsi devices will reply with a specific string, which the
RISC/6000 compares with the strings it has in the Object Data Base. If it
finds the string, it will configure it according to the other attributes
stored in the database for a device returning this string, if it does not
recognise the string, it will classify the device correctly as an 8 mm
2.2 gigabyte tape drive, but not configure it, since it has no knowledge
about the other attributes of this device.

You must therefore define the other attributes and add them to the object
database before your RISC System 6000 will make the device available to you.
The trouble is: The documentation about odme, omadd & friends tells you all
about how to create your own object data base, and how to generate attribute
definitions, and other things you may never have dreamt of, for your object
data base, but it does not tell you which attributes are used in the 
Object Data Base and what significance they have.

This, of course, is done so that your RISC System 6000 does not use devices
in an inappropriate way, and if you remember that you entrust the backup of 
your valuable data to these tapes, then you will certainly agree that only 
the correct use of tape drives will result in a reliable backup system.
Many people just don't realize that only the best quality software and 
hardware will do for IBM customers (quoth my IBM system engineer).

I will post a suitable description file once I have found the exact
parameters - I will have to do similar over the next few weeks.

                         Thomas 

*** This is the operative statement, all previous statements are inoperative.
*   email: cmaae47 @ uk.ac.ic.cc.suna    (Thomas Sippel - Dau)
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