From owner-freebsd-current Fri Mar 31 15:21:25 1995 Return-Path: current-owner Received: (from majordom@localhost) by freefall.cdrom.com (8.6.10/8.6.6) id PAA10766 for current-outgoing; Fri, 31 Mar 1995 15:21:25 -0800 Received: from irz301.inf.tu-dresden.de (irz301.inf.tu-dresden.de [141.76.1.11]) by freefall.cdrom.com (8.6.10/8.6.6) with SMTP id PAA10729 for ; Fri, 31 Mar 1995 15:20:17 -0800 Received: from sax.sax.de by irz301.inf.tu-dresden.de with SMTP (5.67b+/DEC-Ultrix/4.3) id AA23267; Fri, 31 Mar 1995 23:09:44 +0200 Received: by sax.sax.de (8.6.9/8.6.9-s1) with UUCP id XAA22994 for freebsd-current@FreeBSD.org; Fri, 31 Mar 1995 23:09:44 +0200 Received: (from j@localhost) by uriah.heep.sax.de (8.6.11/8.6.9) id XAA09495 for freebsd-current@FreeBSD.org; Fri, 31 Mar 1995 23:07:37 +0200 From: J Wunsch Message-Id: <199503312107.XAA09495@uriah.heep.sax.de> Subject: Re: Floppy drive access overhead? To: freebsd-current@FreeBSD.org (FreeBSD-current users) Date: Fri, 31 Mar 1995 23:07:36 +0200 (MET DST) In-Reply-To: <199503311202.EAA02623@estienne.cs.berkeley.edu> from "Justin T. Gibbs" at Mar 31, 95 04:02:07 am Reply-To: joerg_wunsch@uriah.heep.sax.de (Joerg Wunsch) X-Phone: +49-351-2012 669 X-Mailer: ELM [version 2.4 PL23] Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Content-Length: 746 Sender: current-owner@FreeBSD.org Precedence: bulk As Justin T. Gibbs wrote: > [formatting floppies] > . Under FreeBSD, I get "jerky" system > behavior at best. Does anyone know why we have this problem > and how it can be fixed? I can't confirm this. Adaptecs however (at least the old ones) are known to be broken. They hog the bus for too long and cause the floppy driver to get DMA overruns all the time when heavy SCSI activity is going on. The floppy driver silently retries the failed transmissions, but it costs allot of time (and is absolutely not optimized -- it simply waits a whole revolution instead of trying other sectors first). -- cheers, J"org joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ Never trust an operating system you don't have sources for. ;-)