From owner-freebsd-current Tue May 16 05:17:34 1995 Return-Path: current-owner Received: (from majordom@localhost) by freefall.cdrom.com (8.6.10/8.6.6) id FAA08720 for current-outgoing; Tue, 16 May 1995 05:17:34 -0700 Received: from hda.com (hda.com [199.232.40.182]) by freefall.cdrom.com (8.6.10/8.6.6) with ESMTP id FAA08710 for ; Tue, 16 May 1995 05:17:29 -0700 Received: (dufault@localhost) by hda.com (8.6.9/8.3) id IAA24599; Tue, 16 May 1995 08:18:07 -0400 From: Peter Dufault Message-Id: <199505161218.IAA24599@hda.com> Subject: Re: big files written to scsi harddisk got corrupted To: davidg@Root.COM Date: Tue, 16 May 1995 08:18:07 -0400 (EDT) Cc: current@FreeBSD.org In-Reply-To: <199505161039.DAA01603@corbin.Root.COM> from "David Greenman" at May 16, 95 03:39:18 am X-Mailer: ELM [version 2.4 PL24] Content-Type: text Content-Length: 1253 Sender: current-owner@FreeBSD.org Precedence: bulk David Greenman writes: > > >as on the Syquest. I presume this is a bug in FreeBSD as the drive is > >new and the controller is known to have worked flawlessly in another machine. > >In case you need it here is my configuration: > > > >Adaptec 1542 A SCSI controller (I use its floppy disk controller, too) > > The Adaptec 1542A is known to corrupt data for DMA's that are larger than > 16Kbytes. FreeBSD uses I/O clustering both in the file I/O system and in the > VM system and DMA's are frequently larger than 16Kbytes. There are apparantly > some versions of the 1542A that don't have this problem, but every one that > I've tested does. If you upgrade the controller to a 1542B, the problems > should go away. > Can we just put in a minphys for 16K for the 1542A? It is easy to tell when an adapter says it is a 1542A. We can add a flag argument to disable it if you have a known working board or a clone of some sort that says it is a 1542A. This is what I plan to do once I get a computer I can actually test it on. I don't like making changes I can't test. Peter -- Peter Dufault Real Time Machine Control and Simulation HD Associates, Inc. Voice: 508 433 6936 dufault@hda.com Fax: 508 433 5267