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Date:      Tue, 07 May 1996 17:10:28 -0700
From:      Darryl Okahata <darrylo@hpnmhjw.sr.hp.com>
To:        Tom Proett <proett@nas.nasa.gov>
Cc:        scsi@freebsd.org
Subject:   Re: quantum atlas vs adaptec 
Message-ID:  <199605080010.AA076014229@hpnmhjw.sr.hp.com>
In-Reply-To: Your message of "Tue, 07 May 1996 14:33:33 PDT." <199605072133.OAA27433@tailspin.nas.nasa.gov> 

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> I started from DOS and ran fdisk fine.  Then I tried format.  All went
> well until the end when it was going to write the label.  At this point,
> the system froze with the drive and adaptor busy lights on solid.
> I tried doing a few things with the drive and almost everything resulted
> in a freeze.  I contacted Quantum and they said there was a timing problem
> between the atlas and the adaptec 1742 and gave me a firmware upgrade for
> the disk.  It completed with no error but the freeze still happens.
> Trying to access the disk from FreeBSD results in a freeze as well.

     Perhaps the Quantum is responding to SCSI commands too quickly for
the adapter to handle?  The 1742 is pretty old.

     To the end of this message, I've appended a copy of some posts that
appeared on comp.periphs.scsi some time back (these supposedly do apply
to Atlas drives).  In particular, see item #2 of the first message.

     -- Darryl Okahata
	Internet: darrylo@sr.hp.com

DISCLAIMER: this message is the author's personal opinion and does not
constitute the support, opinion, or policy of Hewlett-Packard, or of the
little green men that have been following him all day.

===============================================================================
From: Ralf-Peter Rohbeck <rrohbeck@qntm.com>
Newsgroups: comp.periphs.scsi
Subject: Re: Can't Low-Level Quantum Capella
Date: 29 Jan 1996 13:40:48 GMT
Organization: Quantum Germany
NNTP-Posting-Host: rprmac.qntm.com

Per Vaihinen <pvaihine@mail.abo.fi> wrote:
>I also had lots of problems with this drive! We changed one unit 5 times
>and eventually they shipped the last one again because they got it to
>work with Adaptec AHA2940. We got the same error message when we tried
>to low-level format with SCSISelect. But it worked! The reason we 
>returned the drive so many times was that it was 6-8 times slower than
>normal drives in formatting and it didn't work on a AHA-1542CF BIOS2.02.
Hi.

I don't know if you saw my earlier post on this. But the Capella works
well with Adaptecs - if you know how to do it. Sorry if your source
didn't have the necessary tech support to get it fixed.
To summarize:
1. The format problem is Adaptec's fault. They try to do a MODE SELECT
   on a mode page that the Capella doesn't have and bail out on the
   returned nonzero status. Several external programs are available that
   do the FORMAT right.
2. The synchronous transfer problems: Also Adaptec's fault. By default,
   the Capella runs at full steam. Unfortunately, on hardware cache hits,
   it returns data so quickly that the host adapter loses the first few
   bytes, which hangs the transmission. There is a bit in the mode pages
   to delay read cache hits by some 15 us so the drive doesn't overrun the
   host adapter. It can be set with e.g. DSP tools which is available
   on the Net (ftp://ftp.rahul.net/pub/lps/hard-disk). Set page 25h
   byte 5 bit 3 (08h).
3. The formatting time: Ok, it takes a lot longer than other vendors'
   drives. But how often do you format a drive? And what do you think
   this says about the effort put into certifying each block?
4. Problems with Fireballs? Not that I know of. The Fireball is the most
   successful product we ever made. The high production numbers lead
   to proportionally increased numbers of failures at equal reliabilty,
   obviously. And the Fireball is a little more reliable than e.g.
   Lightning.
5. Empire: Admitted, the reliabilty of some Empire lots has been less
   than expected. But still, this is bad luck. The failure rates are
   a few percent per year at most.

FWIW, all of the above applies to Atlas drives as well and will probably
also apply to Atlas II.

Cheers,
Ralf-Peter
========================================================================
Ralf-Peter Rohbeck                                     rrohbeck@qntm.com
Quantum GmbH-Application Engineering-Central Europe   (+49) 69-950767-18
Berner Str. 28, 60437 Frankfurt, Germany          fax (+49) 69-950767-91
#include "disclaimer.h"          tech support hotline (+49) 69-950767-26

===============================================================================
From: Ralf-Peter Rohbeck <rrohbeck@qntm.com>
Newsgroups: comp.periphs.scsi
Subject: Re: Can't Low-Level Quantum Capella
Date: Wed, 21 Feb 1996 15:22:05 +0100
Organization: Quantum Germany
Reply-To: rrohbeck@qntm.com

Hi,

Wallace Moore wrote:
> say, why it doesn't offer relative addressing or linked commands?
> My older Micropolis does, incidentally.  Are these SCSI drive
> capabilities irrelevant, or do they have real value?  Or, again,
Nobody really required them so far so we didn't implement them.
There might a use for linking in multi initiator systems, but I never saw 
anyone using relative addressing in disk drives.

> Note that I merely accepted Mr. Rohbeck's assertion that the
> Adaptec mode page (the one that supposedly causes Quantum-drive
> low-level formats to abort) is a "dummy."  That does not count as
> convincing proof.  So, while we're (myself alone, possibly)
> pondering why certain other drive-makers manage to handle that
> "dummy" page effortlessly and without complaint, maybe you could
You got me wrong. This page serves a real purpose, but only in Quantum 
drives designed in Milpitas, with the "Quantum West" SCSI architecture. It 
allows a quicker low level format by setting certain parameters.
The drives designed in Shrewsbury ("Quantum East", i.e. ex Avastor/DEC) 
have a completely different architecture which doesn't offer that feature. 
Now that these drives are called "QUANTUM" instead of "DEC" in the INQUIRY 
data, Adaptec's BIOS tries to set that mode page and fails.
To avoid that, we'd have to implement a dummy mode page in the Quantum East 
SCSI firmware.
There is a quick and dirty fix by changing the INQUIRY vendor name from 
"QUANTUM" to "Quantum" (using different firmware) so the Adaptec BIOS 
doesn't recognize it any more. But I don't like that. The SCSI spec says 
that Quantum's vendor id is "QUANTUM" and doesn't say if it should or 
shouldn't be case sensitive. So, we'd have to bet that all applications 
that need to recognize the vendor name do a case insensitive compare - 
except for Adaptec.

But, in any case:
1. You don't have to low level format any modern drive. It's a waste of 
time.
2. If you still want to, you can use the format program from the EZ-SCSI 
package or our DSP tools.

Cheers,
Ralf-Peter
-- 
========================================================================
Ralf-Peter Rohbeck                                     rrohbeck@qntm.com
Quantum GmbH-Application Engineering-Central Europe   (+49) 69-950767-18
Berner Str. 28, 60437 Frankfurt, Germany          fax (+49) 69-950767-91
#include "disclaimer.h"          tech support hotline (+49) 69-950767-26




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