From owner-freebsd-questions Fri Mar 1 17:04:24 1996 Return-Path: owner-questions Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id RAA23545 for questions-outgoing; Fri, 1 Mar 1996 17:04:24 -0800 (PST) Received: from genesis.atrad.adelaide.edu.au (genesis.atrad.adelaide.edu.au [129.127.96.120]) by freefall.freebsd.org (8.7.3/8.7.3) with ESMTP id RAA23539 for ; Fri, 1 Mar 1996 17:04:21 -0800 (PST) Received: from msmith@localhost by genesis.atrad.adelaide.edu.au (8.6.12/8.6.9) id LAA04099; Sat, 2 Mar 1996 11:36:09 +1030 From: Michael Smith Message-Id: <199603020106.LAA04099@genesis.atrad.adelaide.edu.au> Subject: Re: Backup problem To: nate@sri.MT.net (Nate Williams) Date: Sat, 2 Mar 1996 11:36:08 +1030 (CST) Cc: tomppa@fidata.fi, questions@freebsd.org In-Reply-To: <199602292321.QAA13183@rocky.sri.MT.net> from "Nate Williams" at Feb 29, 96 04:21:38 pm MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-questions@freebsd.org Precedence: bulk Nate Williams stands accused of saying: > > > My system hangs when I'm doing full backup to DAT drive with tar or > > cpio. > ... > > it takes 5-55 minutes before it happens. > .... > > > I changed bt driver to aha (AMI SCSI controller is compatible with > > buslogic 742a and Adaptec 1542). With aha driver backupping works like > > a charm. Making full backup taked over an hour but it worked > > smoothly. I even tried it twice. Any good explanations? > > Yep, I'll bet the bounce buffer code is enabled on the aha driver and > might not be on the buslogic. > > > > real memory = 33554432 (32768K bytes) > > This is important if you have more than 16MB and your card can't do DMA > above 16MB. > > > > bt0: Bt747S/ 0-(32bit) bus > > The bt driver assumes it can. ... and what hasn't been mentioned is that quite a number of EISA motherboards (the 747 is an EISA board, right?) don't handle DMA above the 16M mark properly (or at all). > Nate -- ]] Mike Smith, Software Engineer msmith@atrad.adelaide.edu.au [[ ]] Genesis Software genesis@atrad.adelaide.edu.au [[ ]] High-speed data acquisition and (GSM mobile) 0411-222-496 [[ ]] realtime instrument control (ph/fax) +61-8-267-3039 [[ ]] Collector of old Unix hardware. "Where are your PEZ?" The Tick [[