From owner-freebsd-scsi Thu Jun 6 04:11:41 1996 Return-Path: owner-freebsd-scsi Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id EAA18787 for freebsd-scsi-outgoing; Thu, 6 Jun 1996 04:11:41 -0700 (PDT) Received: from guardian.fortress.org (fortress.org [199.84.158.128]) by freefall.freebsd.org (8.7.5/8.7.3) with SMTP id EAA18781; Thu, 6 Jun 1996 04:11:36 -0700 (PDT) Received: (from andrew@localhost) by guardian.fortress.org (8.6.12/8.6.12) id HAA04720; Thu, 6 Jun 1996 07:10:26 -0400 Date: Thu, 6 Jun 1996 07:10:25 -0400 (EDT) From: Andrew Webster Reply-To: andrew@pubnix.net To: Dror Matalon cc: freebsd-scsi@FreeBSD.ORG, freebsd-isp@FreeBSD.ORG Subject: Re: ERROR info:747d9d asc:11,0 Unrecovered read error, other SCSI , issues In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-scsi@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk On Wed, 5 Jun 1996, Dror Matalon wrote: > Hi Folks, > > We're using an NCR 53c825 wide scsi controller with 3 > Quantum XP34300W 4.3 Fast Wide SCSI drives on a pentium 133 > as our news machine. > > We started getting the messages: > sd0(ncr0:0:0): MEDIUM ERROR info:7476a9 asc:11,0 Unrecovered read error > , retries:4 > sd0(ncr0:0:0): MEDIUM ERROR info:7476a9 asc:11,0 Unrecovered read error > , retries:3 > ... > > These messages always complain about 2 addresses 7476a9 and 747d9d. > We suspect that these are on the swap area of the first disk. Very interesting, I had a bad experience almost a year ago where a system ate two of these Quantum XP34300 drives in two months, and it wasn't a news server! This was a P133 with AHA-2940 with FreeBSD 2.0.5. What I'd noticed in both cases was that when lots of seek activity occurs, occasionally, the drive would stop seeking and a loud "ringing" sound would be heard from the drive for a couple of seconds, and then it would continue seeking. I've seen this in a couple of other vendor's drives as well. I suspect that the head/arm mechanism may start resonating due to the speed at which the seeks are being done, and this may lead to head crashes. In the case of the Quantum drives, both drives, when they failed, had bad spots all over the disks! I don't think the problem was related to heat, as the drive was in an external enclosure with its own fan. After two disks suffering the same fate, I switched the disk for a Seagate and all the problems went away! Bleeding edge technology? Maybe! Andrew Webster - andrew@pubnix.net - http://www.pubnix.net PubNIX Montreal - Connected to the world - Branche au monde 514-990-5911 - P.O. Box 147, Cote St-Luc, Quebec, H4V 2Y3