[4518] in linux-scsi channel archive
Re: What is this error?
daemon@ATHENA.MIT.EDU (Francesco Potorti`)
Sun Aug 9 08:55:35 1998
Date: Sun, 9 Aug 1998 14:53:38 +0200 (CEST)
From: Francesco Potorti` <F.Potorti@cnuce.cnr.it>
To: "Leonard N. Zubkoff" <lnz@dandelion.com>
CC: linux-scsi@vger.rutgers.edu
In-reply-to: <199808080519.WAA13997@dandelion.com> (lnz@dandelion.com)
Thank you very much for your kind answer.
The status 12 error reported is a Data Over Run. This means that the
disk device tried to provide the host adapter with more data than was
requested.
I wonder what happens when you are not on this list :-) Is there a free
source where I can find the meanings of these status messages? Would
it be reasonable to output a more verbose error message?
The above messages show that you have 5 devices connected to the
FlashPoint LW, and you have enabled Ultra SCSI speed for the IBM
disks. The specifications for Ultra SCSI limit the cable length to
1.5 meters if you have more than 4 devices, and also require active
termination at both ends of the chain. Most likely running Ultra
SCSI speed on your SCSI bus is outside the tolerances, and that may
be the cause of the problem. I suggest you limit the SCSI bus to
Fast SCSI-2 (10 MHz) speed and see if you still have problems. It's
possible there is a hardware problem with your FlashPoint or with the
IBM drive, but checking the cabling and termination is always the
first thing to do when diagnosing SCSI problems.
That is what I suspected. All five devices are inside the PC box, and
are connected using two old high quality narrow SCSI cables connected in
series (I fear this is where the specifications are not met). One end
is the BusLogic card itself, and the other end is an active terminator.
One possible source of trouble is that the cable is confined inside the
PC box, so it is twisted and may interfere with itself. Another one may
be the high temperatures we are experiencing here now. Since I usually
dislike air conditioning, the box is running 24 hours a day at
temperatures which may exceed 30C, so maybe an occasional error is not
exceptional. In fact, I have run this setup without errors for some
months.
Again, thanks for your kind suggestions.
--
Francesco Potorti` (researcher) Voice: +39-050-593 203 (op. 211)
Computer Networks Group Fax: +39-050-904052
CNUCE-CNR, Via Santa Maria 36 Email: F.Potorti@cnuce.cnr.it
56126 Pisa - Italy Web: http://fly.cnuce.cnr.it/
-
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@vger.rutgers.edu
