From owner-freebsd-scsi Mon Apr 21 08:48:45 1997 Return-Path: Received: (from root@localhost) by freefall.freebsd.org (8.8.5/8.8.5) id IAA24667 for freebsd-scsi-outgoing; Mon, 21 Apr 1997 08:48:45 -0700 (PDT) Received: from pluto.plutotech.com (root@pluto100.plutotech.com [206.168.67.137]) by freefall.freebsd.org (8.8.5/8.8.5) with ESMTP id IAA24657 for ; Mon, 21 Apr 1997 08:48:42 -0700 (PDT) Received: from narnia.plutotech.com (narnia.plutotech.com [206.168.67.130]) by pluto.plutotech.com (8.8.5/8.8.3) with ESMTP id JAA10492; Mon, 21 Apr 1997 09:48:39 -0600 (MDT) Message-Id: <199704211548.JAA10492@pluto.plutotech.com> X-Mailer: exmh version 2.0beta 12/23/96 To: Alan Judge cc: "Justin T. Gibbs" , freebsd-scsi@freebsd.org Subject: Re: Vendor specific ASCQ SCSI errors in 2.2-STABLE In-reply-to: Your message of "Mon, 21 Apr 1997 16:40:20 BST." <199704211540.QAA03447@indigo.ie> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Mon, 21 Apr 1997 09:47:05 -0600 From: "Justin T. Gibbs" Sender: owner-freebsd-scsi@freebsd.org X-Loop: FreeBSD.org Precedence: bulk >If not, maybe I should try to get an explanation of the code from >Quantum. It may be hard to get. We just received the latest tech ref from them, so you'll have to get above one of their tech support drones in order to get a real response. >Justin> If this is indeed the case, I would suspect a cabling or >Justin> termination problem that rears it's ugly head only under heavy >Justin> load. > >The setup is fairly simple. Eight disks, all internal. Four each on >channels of a 3940UW. A single ribbon cable connects each set, and >termination is enabled on the last drive in each chain. The only >unusual feature is that all the disks are in hot-swap cannisters, so >there's some internal cabling there. Your setup appears to be sound. Using a single ribbon cable for all of the ultra disks is one of the best ways, according to an Adaptec study, to ensure correct Ultra SCSI operation. Hmm. >At the moment, I only get the error on sd0 and even there it only >happens once a day or so. Any ideas on where to start narrowing down >the problem. My first hunch would be a bogus connector somewhere in the system which is putting a large capacitive load on the bus. I would try changing out a canister at a time with a known good one. If you can afford to steal a canister from the other bus, the one that seems to work, that should allow you to be "scientific" about it. -- Justin T. Gibbs =========================================== FreeBSD: Turning PCs into workstations ===========================================