Skip site navigation (1)Skip section navigation (2)
Date:      Mon, 12 Apr 1999 10:32:25 -0700
From:      Darryl Okahata <darrylo@sr.hp.com>
To:        Steve Howe <groggy@iname.com>
Cc:        freebsd-scsi@FreeBSD.ORG, freebsd-questions <questions@FreeBSD.ORG>
Subject:   Re: board not responding 
Message-ID:  <199904121732.KAA09157@mina.sr.hp.com>
In-Reply-To: Your message of "Fri, 09 Apr 1999 23:20:48 -0800." <Pine.BSF.3.96.990409224603.1844A-100000@en26.l1.net> 

next in thread | previous in thread | raw e-mail | index | archive | help
Steve Howe <groggy@iname.com> wrote:

> > > ahc0 <Adaptec 2940 Ultra SCSI adapter> rev 1 int a irq 10 on pci:0:10:0
> > > ahc0: aic7800 Wide Channel, SCSI Id=7, 16 SCBs
> > > ahc0 waiting for scsi devices to settle
> > > (ahc0:0:0): "IBM DDRS-34560D DC1B" type 0 fixed SCSI 2
> > > sd0(ahc0:0:0): Direct-Access 4357MB (8925000 512 byte sectors)
> > > ahc0: board is not responding
> 
> > > (term)                (auto)                          (term)
> > > IBM DDRS-34560 HD <-> 2940UW <-> Toshiba 6401B CD <-> HP 4020 CD/RW
> > >                 68 pin     50 pin               50 pin
> 
> i hear what you are saying, but don't know what it means.
> usually when i hear "single-ended", i think "as opposed to differential".
> 
> the IBM spec sheets for the drive state:
> "Enable SCSI terminator SE 50/68 pin"

     Sorry, I was a bit unclear in my last posting.  Here's what I'm
trying to say:

* The IBM Ultrastar 9ES (which is what you and I have) comes in both
  single-ended and LVD (Low-Voltage Differential) versions.

  [ Yes, the IBM drives do come in 68-pin LVD versions. ]

* LVD drives can often be used with single-ended controllers.

* The "IBM DDRS-34560D DC1B" is an LVD drive.  On the drive, look for
  "LVD" on the little white label.

* LVD drives DO NOT HAVE PROVISION FOR ON-DRIVE TERMINATION.  LVD drives 
  cannot be used to terminate the SCSI bus.  You need an external
  terminator.

* In the case of the IBM DDRS-34560D, the jumper that controls
  "termination" does not control termination (LVD drives don't have
  any provision for on-drive termination).  Instead, this jumper
  controls whether or not the drive runs in LVD or plain old
  single-ended mode.

* IBM really does make LVD drives in a 68-pin configuration.  See the
  first page of this PDF file:

	http://www.storage.ibm.com/techsup/hddtech/ddrs/ddrs.pdf

  Note the line that says, "SCSI-3 FAST-40 (68 & 80-pin (L)ow (V)oltage
  (D)ifferential)".

* If you still don't believe you have an LVD drive, check out these
  DejaNews postings:

	http://www.dejanews.com/[ST_rn=ps]/getdoc.xp?AN=441444978
	http://www.dejanews.com/[ST_rn=ps]/getdoc.xp?AN=436967059
	http://www.dejanews.com/[ST_rn=ps]/getdoc.xp?AN=436728277

* For more info, Adaptec's web site has some good info on LVD:

	http://www.adaptec.com/products/solutions/ultra2.html

> but when i add the Toshiba, with either the IBM or the HP
> in addition, the SCSI bus dies as shown above.

     ... which is consistent with termination problems (among other
possible things).

--
	Darryl Okahata
	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.


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-scsi" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199904121732.KAA09157>